What is antispasmodic

Antispasmodic is any drug or compound that prevents or relieves muscle spasms, mainly ones originating from smooth muscle contractions of the stomach, bladder and intestines. Antispasmodic compounds are currently used to reduce anxiety, emotional and musculoskeletal tension, and irritability,
relax smooth muscle in the gastrointestinal tract, bladder and lung and can be used for gastrointestinal, urological or respiratory conditions associated with spasm and dysmotility. Antispasmodics are sometimes given for abdominal pain to relieve irritable bowel syndrome (IBS) symptoms.

There is two main classes of antispasmodic, the anticholinergics and drugs that are direct smooth muscle relaxants.

Anticholinergics are agents that decrease or block the actions of acetylcholine on its parasympathetic nervous system receptors on smooth muscle cells, glands and the central nervous system. Cholinergic receptors are usually categorized as nicotinic or muscarinic. Anticholinergics often demonstrate differential antagonism for different receptors types and subtypes, accounting in part for their variety of actions and clinical usefulness for different conditions.

The anticholinergics in clinical use include natural, semisynthetic and synthetic compounds that demonstrate a multitude of actions on smooth muscle cells and the parasympathetic nervous system. Anticholinergics have antisecretory activities and decrease nasal and bronchial secretions, salivation, lacrimation, sweating and gastric acid production, and can be used to decrease secretions in allergic and inflammatory diseases. Anticholinergics relax smooth muscle in the gastrointestinal tract, bladder and lung and can be used for gastrointestinal, urological or respiratory conditions associated with spasm and dysmotility. Some anticholinergics have antiemetic properties and are used to prevent nausea and vomiting from motion sickness or during the perioperative period. Anticholinergics increase heart rate and can be used to treat bradycardia. They are also used to reverse cholinergic overstimulation caused by cholinesterase inhibitors and neuromuscular blockers in anesthesia.

Direct smooth muscle relaxants. Mebeverine is an antispasmodic that has been used in the management of IBS for many years. Mebeverine is a musculotropic agent that has antispasmodic activity and regulatory effects on the bowel function ¹. However, the results of this meta-analysis ² demonstrate that the clinical improvement and relief of abdominal pain observed for mebeverine is not statistically significant compared to placebo. The meta-analysis also showed that mebeverine 200 mg is as effective as mebeverine 135 mg in the clinical improvement and relief of abdominal pain. The results also indicated no significant adverse effects for mebeverine 200 mg. During oral administration at doses of 135-270 mg three times daily, it shows no typical anticholinergic side effects, such as dry mouth, blurred vision, and impaired micturition ². The incidence of side effects caused by mebeverine has not been demonstrated to be higher than that of a placebo ³. Moreover, mebeverine 200 mg twice daily was shown to be therapeutically equivalent to mebeverine 135 mg three times daily in treatment of abdominal pain in IBS without a higher incidence of adverse effects. Studies also confirmed that both formulations of mebeverine were regarded as effective in more than 80% of cases. Tolerability was also excellent, with only few adverse effects and compliance close to 100% for most of patients. Reducing the number of daily doses from three to two is an advantage of the mebeverine extended release capsule in terms of patients’ compliance ⁴. Although the effects of mebeverine on clinical improvement and relief of abdominal pain are not statistically significant, it could be considered clinically effective until more studies are added to this meta-analysis to increase the power of the conclusions ². Mebeverine is now sold in approximately 56 countries, and its efficacy and tolerability have been demonstrated in 10 controlled studies and in many open clinical trials ³.

Peppermint oil also have direct smooth muscle relaxing activity. Peppermint oil is used as antispasmodic for pain associated with IBS ⁵. Peppermint oil blocks calcium channels in intestinal smooth muscle ⁶, inexpensive and seems to work ⁷.

Table 1. Synthetic antispasmodic compounds used in medicine

Specific anticholinergic agents in clinical use are listed below with common brand name(s) and major use (G=gastrointestinal, N=nausea and motion sickness, R=respiratory, U=urological). General references to the safety and hepatotoxicity of anticholinergics are given at the end of this overview section and are not repeated in the individual drug descriptions.

Anticholinergics used in Parkinson’s disease include benztropine (Cogentin), biperiden (Akineton) and trihexyphenidyl (Artane).

The natural or semisynthetic belladonna alkaloids include atropine (generic), hyoscyamine (Anaspaz: urological, gastrointestinal) and scopolamine (Scopace, Transderm Scop, nausea and motion sickness).

The synthetic quaternary ammonium derivatives have a bulky ammonium side chain that makes them less likely to cross membranes, including the blood brain barrier, and therefore less likely to have central nervous system effects. Anticholinergic quaternary ammonium derivatives include aclidinium (Tudorza Pressair, respiratory), clinidium (Quarzan: now withdrawn), darifenacin (Enablex, urological), flavoxate (Urispas, urological), glycopyrrolate (Robinul, gastrointestinal), ipratropium (Atrovent, respiratory), mepenzolate (Cantil, gastrointestinal), methscopolamine (generic), propantheline (Pro-Banthine, gastrointestinal) and tiotropium (Tiova, respiratory).

The synthetic tertiary anticholinergics include dicyclomine (Bentyl, gastrointestinal), fesoterodine (Toviaz, urological), homatropine (generic), oxybutynin (Ditropan, urological), solifenacin (VESIcare, urological), tolterodine (Detrol, urological), and trospium (Sanctura, urological).

Bladder antispasmodic

Medications are available for people with bladder control problems marked by sudden, intense urinary urges and urine leakage (overactive bladder and urge incontinence). Fewer medication options exist for urine leakage prompted by movement or activity, such as coughing, sneezing or heavy lifting (stress incontinence).

Anticholinergic drugs block the action of a chemical messenger — acetylcholine — that sends signals to your brain that trigger abnormal bladder contractions associated with overactive bladder. These bladder contractions can make you feel the need to urinate even when your bladder isn’t full.

Anticholinergic medications include (see description of individual drug below):

• Oxybutynin (Ditropan XL, Oxytrol)
• Tolterodine (Detrol)
• Darifenacin (Enablex)
• Solifenacin (Vesicare)
• Trospium
• Fesoterodine (Toviaz)

These medications are usually given as a pill or tablet that you take by mouth. Oxybutynin is also available as a cream or skin patch that delivers a continuous amount of medication.

It can take several weeks before your symptoms begin to improve on this type of medication. It might take 12 weeks to have the full effect.

Anticholinergics side effects

The most common side effects of anticholinergics are dry mouth and constipation. An extended-release form, which you take once a day, might cause fewer side effects than the immediate-release versions, which are usually taken multiple times a day.

To counteract dry mouth, try sucking hard candy or chewing gum to produce more saliva. Other less common side effects include heartburn, blurry vision, rapid heartbeat (tachycardia), flushed skin, urinary retention and cognitive side effects, such as impaired memory and confusion.

If you use the oxybutynin skin patch, it might cause skin irritation. Your doctor might suggest that you rotate the location of your patch.

Antispasmodic for IBS

Irritable bowel syndrome (IBS) is a group of symptoms that occur together, including repeated pain in your abdomen and changes in your bowel movements, which may be diarrhea, constipation, or both. With IBS, you have these symptoms without any visible signs of damage or disease in your digestive tract.

IBS is a functional gastrointestinal (GI) disorder. Functional GI disorders, which doctors now call disorders of gut-brain interactions, are related to problems with how your brain and your gut work together. These problems can cause your gut to be more sensitive and change how the muscles in your bowel contract. If your gut is more sensitive, you may feel more abdominal pain and bloating. Changes in how the muscles in your bowel contract lead to diarrhea, constipation, or both.

To treat IBS with diarrhea, your doctor may recommend:

• Lubiprostone (Amitiza). Lubiprostone can increase fluid secretion in your small intestine to help with the passage of stool. It’s approved for women who have IBS with constipation, and is generally prescribed only for women with severe symptoms that haven’t responded to other treatments.
• Rifaximin (Xifaxan). This antibiotic can decrease bacterial overgrowth and diarrhea.
• Eluxadoline (Viberzi). Eluxadoline can ease diarrhea by reducing muscle contractions and fluid secretion in the intestine, and increasing muscle tone in the rectum. Side effects can include nausea, abdominal pain and mild constipation. Eluxadoline has also been associated with pancreatitis, which can be serious and more common in certain individuals.
• Alosetron (Lotronex), which is prescribed only to women and is prescribed with special warnings and precautions. Alosetron is designed to relax the colon and slow the movement of waste through the lower bowel. Alosetron can be prescribed only by doctors enrolled in a special program, is intended for severe cases of diarrhea-predominant IBS in women who haven’t responded to other treatments, and isn’t approved for use by men. It has been linked to rare but important side effects, so it should only be considered when other treatments aren’t successful.
• Your doctor might also prescribe a bile acid binder, such as cholestyramine (Prevalite), colestipol (Colestid) or colesevelam (Welchol). Bile acid binders can cause bloating.

To treat IBS with constipation, your doctor may recommend:

• Fiber supplements, when increasing fiber in your diet doesn’t help. Taking a supplement such as psyllium (Metamucil) with fluids may help control constipation.
• Laxatives. If fiber doesn’t help symptoms, your doctor may prescribe magnesium hydroxide oral (Phillips’ Milk of Magnesia) or polyethylene glycol (Miralax).
• Lubiprostone (Amitiza)
• Linaclotide (Linzess). Linaclotide also can increase fluid secretion in your small intestine to help you pass stool. Linaclotide can cause diarrhea, but taking the medication 30 to 60 minutes before eating might help.
• Plecanatide (Trulance)

Other medicines may help treat pain in your abdomen, including:

• Anticholinergic medications. Medications such as dicyclomine (Bentyl) can help relieve painful bowel spasms. They are sometimes prescribed for people who have bouts of diarrhea. These medications are generally safe but can cause constipation, dry mouth and blurred vision
• Antidepressants, such as low doses of tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs)
  • Tricyclic antidepressants. This type of medication can help relieve depression as well as inhibit the activity of neurons that control the intestines to help reduce pain. If you have diarrhea and abdominal pain without depression, your doctor may suggest a lower than normal dose of imipramine (Tofranil), desipramine (Norpramine) or nortriptyline (Pamelor). Side effects — which might be reduced if you take the medication at bedtime — can include drowsiness, blurred vision, dizziness and dry mouth.
  • Selective serotonin reuptake inhibitors (SSRIs) antidepressants. Selective serotonin reuptake inhibitor (SSRI) antidepressants, such as fluoxetine (Prozac, Sarafem) or paroxetine (Paxil), may help if you’re depressed and have pain and constipation.
• Coated peppermint oil capsules
• Pain medications. Pregabalin (Lyrica) or gabapentin (Neurontin) might ease severe pain or bloating.

Follow your doctor’s instructions when you use medicine to treat IBS. Talk with your doctor about possible side effects and what to do if you have them.

Antispasmodic drugs

Darifenacin

Darifenacin is an anticholinergic and antispasmotic agent used to treat urinary incontinence and overactive bladder syndrome (a condition in which the bladder muscles contract uncontrollably and cause frequent urination, urgent need to urinate, and inability to control urination). Darifenacin works by relaxing the bladder muscles to prevent urgent, frequent, or uncontrolled urination. Darifenacin was approved for use in the United States in 2004 and indications include urinary urge incontinence and overactive bladder syndrome.

Darifenacin is anticholinergic agent with a degree of selectivity for the M3 subtype of muscarinic acetylcholine receptors which is found predominantly in the smooth muscle of the bladder. Darifenacin increases bladder capacity and decreases bladder contractions and the urgency of urination.

Darifenacin is available in extended release (long-acting) tablets of 7.5 and 15 mg under the brand name Enablex. The recommended adult oral dose is 7.5 to 15 mg once daily with plenty of liquid. Darifenacin may be taken with or without food. Take darifenacin at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take darifenacin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not split, chew, or crush them.

Your doctor will start you on a low dose of darifenacin and may increase your dose after 2 weeks.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

Darifenacin common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, and urinary retention. Because of its selectivity for the M3 muscarinic receptor, darifenacin is believed to be less likely than other anticholinergic agents to cause central nervous system effects such as restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Darifenacin special precautions

Before taking darifenacin:

• tell your doctor and pharmacist if you are allergic to darifenacin or any other medications.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antidepressants such as amitriptyline (Elavil), amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Adapin, Sinequan), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); antihistamines; clarithromycin (Biaxin); flecainide (Tambocor); ipratropium (Atrovent); itraconazole (Sporanox); ketoconazole (Nizoral); medications for irritable bowel disease, motion sickness, Parkinson’s disease, ulcers, or urinary problems; nefazodone (Serzone); nelfinavir (Viracept); ritonavir (Norvir); and thioridazine (Mellaril). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  tell your doctor if you have or have ever had urinary obstruction (a blockage of urine flowing out of the bladder), any type of blockage in the digestive system, benign prostatic hypertrophy (enlargement of the prostate), severe constipation, ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum), myasthenia gravis (a disorder of the nervous system that causes muscle weakness), glaucoma, or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking darifenacin, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking darifenacin.
• you should know that darifenacin may cause blurred vision or make you dizzy. Do not drive a car or operate machinery until you know how this medication affects you.
• you should know that darifenacin causes decreased sweating, which may cause heat prostration (collapse because of high body temperature) in hot weather.

Darifenacin side effects

Darifenacin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• constipation
• upset stomach
• stomach pain
• diarrhea
• weakness
• dry eyes

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• difficulty urinating or being unable to urinate
• burning pain during urination
• rash
• itching

Darifenacin may cause other side effects. Call your doctor if you have any unusual problems while taking darifenacin.

Symptoms of darifenacin overdose may include:

• vision problems

Dicyclomine

Dicyclomine is an anticholinergic agent used to treat gastrointestinal conditions such as acid peptic disease and irritable bowel syndrome (IBS). Dicyclomine relieves muscle spasms in the gastrointestinal tract by blocking the activity of a certain natural substance in the body.

Dicyclomine was approved for use in the United States for the treatment of peptic ulcer disease in 1996, but is now more commonly used as an antispasmotic to treat irritable bowel syndrome.

Dicyclomine is synthetic tertiary amine, antispasmotic and anticholinergic agent which inhibits the muscarinic actions of acetylcholine on autonomic nerve endings, decreasing gastrointestinal secretions and intestinal motility. Dicyclomine has broad activity against muscarinic acetylcholine receptors, but has been used largely for gastrointestinal conditions including peptic ulcer disease and gastrointestinal conditions associated with pain and spasm.

Dicyclomine is available in capsules and tablets of 10 and 20 mg generically and under the brand name Bentyl. Oral syrups and solutions for injection are also available. The typical oral dose in adults is 10 to 20 mg four times daily. To help you remember to take dicyclomine, take it around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dicyclomine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of dicyclomine and gradually increase your dose.

Dicyclomine common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, urinary retention, anxiety, restlessness and delusions. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Dicyclomine special precautions

Before taking dicyclomine:

• tell your doctor and pharmacist if you are allergic to dicyclomine or any other medications.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: amantadine (Symmetrel); antacids; antidepressants such as amitriptyline (Elavil), amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Adapin, Sinequan), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); antihistamines; diet pills; digoxin (Lanoxin); ipratropium (Atrovent); isosorbide (Imdur, Ismo, Isordil, others); medications for anxiety, asthma, glaucoma, irregular heartbeat, mental illness, motion sickness, Parkinson’s disease, seizures, ulcers, or urinary problems; metoclopramide (Reglan); monoamine oxidase (MAO) inhibitors, including phenelzine (Nardil) and tranylcypromine (Parnate); narcotic pain relievers such as meperidine (Demerol); nitroglycerin (Nitro-Bid, Nitrostat, others); sedatives; sleeping pills; and tranquilizers. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had glaucoma; ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum); an enlarged prostate (prostatic hyperplasia); difficulty urinating; esophageal reflux (heartburn); a blockage in the gastrointestinal tract; myasthenia gravis; high blood pressure; an overactive thyroid gland (hyperthyroidism); nerve disease (autonomic neuropathy); heart failure; rapid or pounding heartbeat; hiatal hernia; or liver, kidney, or heart disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking dicyclomine, call your doctor. Do not breast-feed while taking this medication.
• talk to your doctor about the risks and benefits of taking dicyclomine if you are 65 years of age or older. Older adults should not usually take dicyclomine because it is not as safe or effective as other medications that can be used to treat the same condition.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking dicyclomine.
• you should know that dicyclomine may make you drowsy or cause blurred vision. Do not drive a car or operate machinery until you know how this medication affects you.
• remember that alcohol can add to the drowsiness caused by this medication.
• you should know that dicyclomine reduces the body’s ability to cool off by sweating. In very high temperatures, dicyclomine can cause fever and heat stroke.

Dicyclomine side effects

Dicyclomine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• upset stomach
• vomiting
• constipation
• stomach pain
• gas or bloating
• loss of appetite
• dizziness
• tingling
• headache
• drowsiness
• weakness
• blurred vision
• double vision
• difficulty urinating

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

• hot, flushed, dry skin
• confusion
• forgetfulness
• seeing things or hearing voices that do not exist (hallucinating)
• unsteadiness
• coma
• anxiety
• excessive tiredness
• difficulty falling asleep or staying asleep
• excitement
• inappropriate mood
• muscle weakness
• rapid or pounding heartbeat
• fainting
• hives
• skin rash
• itching
• difficulty breathing or swallowing

Dicyclomine may cause other side effects. Call your doctor if you have any unusual problems while taking dicyclomine.

Symptoms of dicyclomine overdose may include the following:

• headache
• upset stomach
• vomiting
• blurred vision
• dilated pupils
• hot, dry skin
• dizziness
• dry mouth
• difficulty swallowing
• nervousness
• excitement
• seeing things or hearing voices that do not exist (hallucinating)

Fesoterodine

Fesoterodine is an anticholinergic and antispasmotic agent used to treat urinary incontinence and overactive bladder syndrome (a condition in which the bladder muscles contract uncontrollably and cause frequent urination, urgent need to urinate, and inability to control urination). Fesoterodine works by relaxing the bladder muscles to prevent urgent, frequent, or uncontrolled urination.

Fesoterodine was approved for use in the United States in 2008, and indications include urinary urge incontinence and overactive bladder syndrome.

Fesoterodine is anticholinergic agent which blocks the muscarinic acetylcholine receptors (antimuscarinic), particularly those found in the smooth muscle of the bladder. Fesoterodine increases bladder capacity and decreases bladder contractions and the urgency of urination.

Fesoterodine is formulated in an extended release (long-acting) formulation and has a quarternary ammonium group that makes it less likely to cross the blood brain barrier. Fesoterodine is available in tablets of 4 and 8 mg under the brand name Toviaz. The recommended adult oral dose is 4 to 8 mg once daily with or without food. Take fesoterodine at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take fesoterodine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole with plenty of liquid; do not split, chew, or crush them.

Your doctor may start you on a low dose of fesoterodine and increase your dose if your symptoms are not controlled. Talk to your doctor about how fesoterodine works for you

Your symptoms should begin to improve during the first few weeks of your treatment with fesoterodine. However, it may take up to 12 weeks for you to feel the full benefit of fesoterodine. Tell your doctor if your symptoms do not improve after you have taken fesoterodine for several weeks.

Fesoterodine may help control your symptoms, but it will not cure your condition. Continue to take fesoterodine even if you feel well. Do not stop taking fesoterodine without talking to your doctor. If you stop taking fesoterodine, your symptoms may return.

Fesoterodine common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, and urinary retention. Because of its structure, fesoterodine is believed to be less likely than other anticholinergic agents to cause central nervous system effects such as restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Fesoterodine special precautions

Before taking fesoterodine:

• tell your doctor and pharmacist if you are allergic to fesoterodine, tolterodine (Detrol, Detrol LA), any other medications, or any of the ingredients in fesoterodine tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antihistamines; certain antifungals such as itraconazole (Sporanox) and ketoconazole (Nizoral); clarithromycin (Biaxin); diltiazem (Cardizem, Cartia XT, Dilacor XR®, others); erythromycin (ERY-C, Ery-Tab); certain HIV protease inhibitors including indinavir (Crixivan), nelfinavir (Viracept), and ritonavir (Norvir); ipratropium (Atrovent); medications for irritable bowel disease, motion sickness, Parkinson’s disease, or ulcers; other medications for urinary problems; and verapamil (Calan, Covera-HS, Isoptin SR, Verelan). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you are unable to empty your bladder, and if you have or have ever had slowed or delayed emptying of your stomach, or glaucoma (increased pressure in the eye that may lead to vision loss). Your doctor may tell you not to take fesoterodine.
• tell your doctor if you have or have ever had a slow or weak urine stream, constipation, any conditions that affect your stomach or intestines, myasthenia gravis (a disease that causes severe muscle weakness), or liver or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking fesoterodine, call your doctor.
  you should know that fesoterodine may cause drowsiness and blurred vision. Do not drive a car or operate machinery until you know how this medication affects you.
• ask your doctor about the safe use of alcoholic beverages while you are taking fesoterodine. Alcohol can add to the drowsiness caused by this medication.
• you should know that fesoterodine may make it harder for your body to cool down when it gets very hot. Avoid exposure to extreme heat, and call your doctor or get emergency medical treatment if you have fever or other signs of heat stroke such as dizziness, upset stomach, headache, confusion, and fast pulse after you are exposed to heat.

Fesoterodine side effects

Fesoterodine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• constipation
• difficulty emptying the bladder
• dry eyes
• dry throat
• cough
• back pain

Some side effects can be serious. If you experience any of these symptoms, stop taking fesoterodine and get emergency medical treatment:

• swelling of the face, throat, tongue, or lips
• hoarseness
• difficulty swallowing or breathing

Fesoterodine may cause other side effects. Call your doctor if you have any unusual problems while you are taking fesoterodine.

Symptoms of fesoterodine overdose may include the following:

• blurred vision
• hot. dry and red skin
• dry mouth
• difficulty emptying your bladder
• rapid heartbeat
• rapid breathing
• nausea or vomiting
• upper body rash
• confusion
• hallucinations (seeing things or hearing voices that do not exist)
• anxiety
• restlessness
• coma (loss of consciousness for a period of time)

Glycopyrrolate

Glycopyrrolate is an anticholinergic agent used to treat gastrointestinal conditions associated with intestinal spasm and to decrease secretions during anesthesia. Glycopyrrolate has been used largely for gastrointestinal conditions including peptic ulcer disease, gastrointestinal spasm and irritable colon. Glycopyrrolate was approved for use in the United States in 1961 but is now not commonly used for gastrointestinal conditions, having been replaced by more effective antiulcer agents.

Glycopyrrolate is a synthetic quaternary ammonium anticholinergic agent which inhibits the muscarinic actions of acetylcholine on autonomic nerve endings, decreasing respiratory and gastrointestinal secretions and intestinal motility. Glycopyrrolate has broad activity against muscarinic acetylcholine receptors, but its highly polar quaternary ammonium group makes it less likely to cross lipid membranes such as the blood brain barrier, which is believed to decrease the potential for central nervous system effects.

Glycopyrrolate is available in tablets of 1 and 2 mg in several generic forms and under the brand name Robinul. The typically recommended oral dose in adults is 1 to 2 mg two to three times daily. It is also available in a solution for parenteral injection for use during anesthesia and intubation to block vagal reflexes and reduce salivary, tracheal, bronchial and gastric secretions.

Glycopyrrolate common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, and urinary retention. Because of its structure, glycopyrrolate is believed to be less likely than other anticholinergics to cross the blood brain barrier and cause central nervous system effects such as restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Glycopyrrolate special precaution

Before taking glycopyrrolate:

• tell your doctor and pharmacist if you are allergic to glycopyrrolate, any other medications, or any of the ingredients in glycopyrrolate tablets or solution. Ask your pharmacist for a list of the ingredients..
• tell your doctor if you are taking extended-release (long-acting) potassium chloride tablets or capsules. Your doctor may tell you not to take glycopyrrolate if you are taking this medication.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: amantadine (Symmetrel); atenolol (Tenormin, in Tenoretic); digoxin (Lanoxin); levodopa (in Rytary, in Sinemet, in Stavelo); ipratropium (Atrovent); mediations for anxiety, irritable bowel disease, mental illness, motion sickness, Parkinson’s disease, seizures, ulcers, or urinary problems; sedatives; tranquilizers; and tricyclic antidepressants such as amitriptyline, amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with glycopyrrolate, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
• tell your doctor if you have or have ever had glaucoma; difficulty urinating; a blockage or narrowing of your stomach or intestines, paralytic ileus (condition in which digested food does not move through the intestines) toxic megacolon (a serious or life-threatening widening of the intestine), or myasthenia gravis (a disorder of the nervous system that causes muscle weakness). Your doctor may tell you not to take glycopyrrolate.
• tell your doctor if you have or have ever had enlargement of the prostate, ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum), overactive thyroid, high blood pressure, heart failure, irregular or rapid heartbeats, coronary artery disease, hiatal hernia with reflux, disorders of the nervous system, or kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking glycopyrrolate, call your doctor.
  if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking glycopyrrolate.
  you should know that glycopyrrolate may make you drowsy or cause blurred vision. Do not drive a car or operate machinery until you know how this medication affects you.
• you should know that glycopyrrolate reduces the body’s ability to cool off by sweating. Avoid being in hot or very warm temperatures. If you experience any of the following symptoms, call your doctor immediately: lack of sweating in hot weather; hot, red skin; decreased alertness; loss of consciousness; fast, weak pulse; fast, shallow breathing; or fever.

Glycopyrrolate side effects

Glycopyrrolate may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• blurred vision
• vision problems
• loss of taste
• headache
• nervousness
• confusion
• drowsiness
• weakness
• dizziness
• difficulty falling asleep or staying asleep
• upset stomach
• nausea
• vomiting
• constipation
• bloated feeling
• nasal congestion

Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:

• diarrhea
• rash
• hives
• difficulty breathing or swallowing
• difficulty urinating or unable to urinate

Glycopyrrolate may cause other side effects. Call your doctor if you have any unusual problems while taking glycopyrrolate.

Hyoscyamine

Hyoscyamine as a natural plant alkaloid derivative and anticholinergic that is used to treat mild to moderate nausea, motion sickness, hyperactive bladder or bladder spasms, peptic ulcer disease, diverticulitis, colic, IBS (irritable bowel syndrome), cystitis, pancreatitis and allergic rhinitis. Hyoscyamine works by decreasing the motion of the stomach and intestines and the secretion of stomach fluids, including acid. Hyoscyamine has been used for decades as an antiemetic, antisecretory and antispasmotic agent in the treatment of nausea, motion sickness, allergic rhinitis, gastrointestinal spasm and hypermotility, functional bowel syndrome and hyperactive bladder. Hyoscyamine may also be used to treat certain heart conditions, to control the symptoms of Parkinson’s disease and rhinitis (runny nose), and to reduce excess saliva production. Despite having been used in clinical medicine for decades, hyoscyamine has not been formally approved for many of its common uses in the United States.

Hyoscyamine is a derivative of natural alkaloid found in plants of the Solanacea family such as henbane (Hyoscyamus niger, for which it is named), jimson weed (Datura stramonium), tomatoes (Soanum lycopersicum) and deadly nightshade (Atropa belladonna). Hyoscyamine is the levorotary isomer of atropine and has potent anticholinergic, antimuscarinic activity.

Hyoscyamine is available as tablets, an extended-release (long-acting) capsules, liquids, elixirs, powders, and solutions for injection in both prescription and over-the-counter forms. Common brand names for products that include hyoscyamine are Belladonna Alkaloids, Donnatal, Hyomax, Urogesic, and Cyclospaz. The recommended adult oral dose varies, but is generally 0.125 to 0.25 mg two to four times daily. The tablets and liquid are usually taken three or four times a day. The extended-release capsules are usually taken twice a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take hyoscyamine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the extended-release tablets whole; do not split, chew, or crush them.

Hyoscyamine controls symptoms associated with disorders of the gastrointestinal tract, but it does not cure the disorders. Continue to take hyoscyamine even if you feel well. Do not stop taking hyoscyamine without talking to your doctor.

Hyoscyamine common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, urinary retention, impotence, tachycardia and palpitations, anxiety, restlessness and in some instances agitation and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Hyoscyamine special precautions

Before taking hyoscyamine:

• tell your doctor and pharmacist if you are allergic to hyoscyamine, any other medications, or any of the ingredients in hyoscyamine tablets, capsules, or liquid. Ask your doctor or pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking pr plan to take. Be sure to mention any of the following: amantadine (Symadine, Symmetrel), amitriptyline (Elavil), chlorpromazine (Thorazine), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), fluphenazine (Prolixin), haloperidol (Haldol), imipramine (Tofranil), medications containing belladonna (Donnatal), mesoridazine (Serentil), nortriptyline (Pamelor), perphenazine (Trilafon), phenelzine (Nardil), prochlorperazine (Compazine), promazine (Sparine), promethazine (Phenergan), protriptyline (Vivactil), thioridazine (Mellaril), tranylcypromine (Parnate), trifluoperazine (Stelazine), triflupromazine (Vesprin), trimeprazine (Temaril), and trimipramine (Surmontil). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• be aware that antacids may interfere with hyoscyamine, making it less effective. Take hyoscyamine 1 hour before or 2 hours after antacids.
• tell your doctor if you have or have ever had glaucoma; heart, lung, liver, or kidney disease; a urinary tract or intestinal obstruction; an enlarged prostate; ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum); or myasthenia gravis.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking hyoscyamine, call your doctor.
• talk to your doctor about the risks and benefits of taking hyoscyamine if you are 65 years of age or older. Older adults should not usually take hyoscyamine because it is not as safe and may not be as effective as other medications that can be used to treat the same condition.
• if you are having surgery, including dental surgery, tell your doctor or dentist that you take hyoscyamine.
• you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how hyoscyamine affects you.
• ask your doctor about the safe use of alcohol during your treatment with hyoscyamine. Alcohol can make the side effects of this medication worse.

Hyoscyamine side effects

Hyoscyamine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• dizziness or lightheadedness
• headache
• blurred vision
• flushing (feeling of warmth)
• dry mouth
• constipation
• difficulty urinating
• increased sensitivity to light

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

• diarrhea
• skin rash
• eye pain
• fast or irregular heartbeat

Hyoscyamine may cause other side effects. Call your doctor if you have any unusual problems while you are taking hyoscyamine.

Mepenzolate

Mepenzolate is an anticholinergic agent used to treat gastrointestinal conditions such as acid peptic disease and IBS (irritable bowel syndrome). Mepenzolate has been used largely for gastrointestinal conditions including peptic ulcer disease and gastrointestinal conditions associated with pain and spasm. Mepenzolate is approved for use in the United States for the treatment of peptic ulcer disease but is now not commonly used, having been replaced by more effective antiulcer agents.

Mepenzolate is a synthetic quaternary ammonium anticholinergic agent which inhibits the muscarinic actions of acetylcholine on autonomic nerve endings, decreasing gastrointestinal secretions and intestinal motility. Mepenzolate has broad activity against muscarinic acetylcholine receptors, but its highly polar quaternary ammonium group makes it less likely to cross lipid membranes such as the blood brain barrier, which is believed to decrease the potential for central nervous system effects.

Mepenzolate is available in tablets 25 mg under the brand name Cantil. The typically recommended oral dose in adults is 25 to 50 mg two to four times daily.

Mepenzolate common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, and urinary retention. Because of its structure, mepenzolate is believed to be less likely than other anticholinergics to cross the blood brain barrier and cause central nervous system effects such as restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Oxybutynin

Oxybutynin is a synthetic anticholinergic agent that is used for treatment of urinary incontinence and overactive bladder syndrome (a condition in which the bladder muscles contract uncontrollably and cause frequent urination, urgent need to urinate, and inability to control urination). Oxybutynin is used largely for the treatment of overactive bladder and for symptoms of frequency and urge incontinence. Oxybutynin is also used to control bladder muscles in adults and children older than 6 years of age with spina bifida (a disability that occurs when the spinal cord does not close properly before birth), or other nervous system conditions that affect the bladder muscles. Oxybutynin is in a class of medications called anticholinergics/antimuscarinics. It works by relaxing the bladder muscles.

Oxybutynin was approved for use in the United States in 1975 and is still widely used.

Oxybutynin is synthetic anticholinergic that has specificity for the M1, M2 and M3 subtypes of the muscarinic acetylcholine receptor which are commonly found in bladder smooth muscle.

Oxybutynin is available in regular and extended release tablets as well as oral solutions, syrups, and transdermal creams in various generic forms and under the trade name Ditropan. A transdermal patch formulation is available under the brand name Oxytrol. The usual adult oral dose is 10 to 20 mg daily in divided doses or in a single extended release tablet form.

Swallow the extended-release tablets whole with plenty of water or other liquid. Do not split, chew, or crush the extended-release tablets. Tell your doctor if you cannot swallow tablets.

Use a dose-measuring spoon or cup to measure the correct amount of liquid for each dose, not a household spoon.

Your doctor may start you on a low dose of oxybutynin and gradually increase your dose, not more than once every week.

Oxybutynin may control your symptoms but will not cure your condition. Continue to take oxybutynin even if you feel well. Do not stop taking oxybutynin without talking to your doctor.

You may notice some improvement in your symptoms within the first 2 weeks of your treatment. However, it may take 6–8 weeks to experience the full benefit of oxybutynin. Talk to your doctor if your symptoms do not improve at all within 8 weeks.

Oxybutynin common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, urinary retention, impotence, tachycardia and palpitations, anxiety, restlessness and in some instances agitation and delusions. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Oxybutynin special precautions

Before taking oxybutynin:

• tell your doctor and pharmacist if you are allergic to oxybutynin, any other medications, or any of the ingredients in oxybutynin tablets, extended-release tablets, or syrup. Ask your doctor or pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: amiodarone (Cordarone, Pacerone); certain antibiotics such as clarithromycin (Biaxin), erythromycin (E.E.S., E-Mycin, Erythrocin), and tetracycline (Bristamycin, Sumycin, Tetrex); certain antifungals such as itraconazole (Sporanox),miconazole (Monistat), and ketoconazole (Nizoral); antihistamines; aspirin and other nonsteroidal anti-inflammatory medications (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn); cimetidine (Tagamet); diltiazem (Cardizem, Dilacor, Tiazac); fluvoxamine; ipratropium (Atrovent); iron supplements; certain medications for human immunodeficiency virus (HIV) such as indinavir (Crixivan), nelfinavir (Viracept), and ritonavir (Norvir, in Kaletra); medications for irritable bowel disease, motion sickness, Parkinson’s disease, ulcers, or urinary problems; medications for osteoporosis (a condition in which bones are weak, fragile, and can break easily) such as alendronate (Fosamax), ibandronate (Boniva), and risedronate (Actonel); nefazodone; potassium supplements; quinidine; and verapamil (Calan, Covera, Isoptin, Verelan). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had narrow angle glaucoma (a serious eye condition that may cause vision loss), any condition that stops your bladder from emptying completely, or any condition that causes your stomach to empty slowly or incompletely. Your doctor may tell you not to take oxybutynin.
• tell your doctor if you have or have ever had ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum); gastroesophageal reflux disease (GERD; condition in which the contents of the stomach back up into the esophagus and cause pain and heartburn); hiatal hernia (condition in which a portion of the wall of the stomach bulges outward, and may cause pain and heartburn); hyperthyroidism (condition in which there is too much thyroid hormone in the body); myasthenia gravis (a disorder of the nervous system that causes muscle weakness); fast or irregular heartbeat; high blood pressure; benign prostatic hypertrophy (BPH, enlargement of the prostate, a male reproductive organ); or heart, liver, or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking oxybutynin, call your doctor.
• talk to your doctor about the risks and benefits of taking oxybutynin tablets or syrup if you are 65 year of age or older. Older adults should not usually take oxybutynin tablets or syrup because they are not as safe and may not be as effective as other medications that can be used to treat the same condition.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking oxybutynin.
• you should know that this medication may make you drowsy or cause blurred vision. Do not drive a car or operate machinery until you know how this medication affects you.
• talk to your doctor about the safe use of alcohol while you are taking this medication. Alcohol can make the side effects from oxybutynin worse.
• you should know that oxybutynin may make it harder for your body to cool down when it gets very hot. Avoid exposure to extreme heat, and call your doctor or get emergency medical treatment if you have fever or other signs of heat stroke such as dizziness, nausea, headache, confusion, and fast pulse after you are exposed to heat.

Oxybutynin side effects

Oxybutynin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• blurred vision
• dry eyes, nose, or skin
• stomach pain
• constipation
• diarrhea
• nausea
• heartburn
• gas
• change in ability to taste food
• headache
• dizziness
• weakness
• confusion
• sleepiness
• difficulty falling asleep or staying asleep
• nervousness
• flushing
• swelling of the hands, arms, feet, ankles, or lower legs
• back or joint pain

Some side effects can be serious. If you experience the following symptom, call your doctor immediately or get emergency medical treatment:

• rash
• hives
• swelling of the eyes, face, lips, tongue, or throat
• hoarseness
• difficulty breathing or swallowing
• frequent, urgent, or painful urination
• fast, irregular, or pounding heartbeat

Oxybutynin may cause other side effects. Call your doctor if you have any unusual problems while you are oxybutynin.

Symptoms of oxybutynin overdose may include the following:

• restlessness
• uncontrollable shaking of a part of your body
• irritability
• seizures
• confusion
• hallucinations (seeing things or hearing voices that do not exist)
• flushing
• fever
• irregular heartbeat
• vomiting
• difficulty urinating
• slowed or difficult breathing
• inability to move
• coma (loss of consciousness for a period of time)
• memory loss
• agitation
• wide pupils (black circles in the centers of the eyes)
• dry skin

Propantheline

Propantheline is an anticholinergic agent used to treat gastrointestinal conditions associated with intestinal spasm and to decrease secretions during anesthesia. Propantheline has been used largely to alleviate symptoms of irritable bowel syndrome (IBS), painful gastrointestinal motility disorders and acid-peptic ulcer disease. Propantheline was approved for use in the United States in 1953 but is now not commonly used, having been replaced by more effective antiulcer agents.

Propantheline (proe pan’ the leen) is a synthetic quaternary ammonium anticholinergic agent which inhibits the muscarinic actions of acetylcholine on autonomic nerve endings, decreasing respiratory and gastrointestinal secretions and intestinal motility. Propantheline has broad activity against muscarinic acetylcholine receptors, but its highly polar quaternary ammonium group makes it less likely to cross lipid membranes such as the blood brain barrier, which is believed to decrease the potential for central nervous system effects.

Propantheline is available in tablets of 7.5 and 15 mg in generic forms and under the brand name Pro-Banthine. The typically recommended oral dose in adults is 7.5 to 15 mg three times daily and 30 mg at bedtime.

Propantheline common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, and urinary retention. Because of its structure, propantheline is believed to be less likely than other anticholinergics to cross the blood brain barrier and cause central nervous system effects such as restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Propantheline special precautions

Before taking propantheline:

• tell your doctor and pharmacist if you are allergic to propantheline, any other medications, or any of the ingredients in propantheline tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements,and herbal products you are taking or plan to take. Be sure to mention any of the following: amantadine (Symmetrel), antihistamines, digoxin (Lanoxin), disopyramide (Norpace), glutethimide (Doriden), levodopa (Larodopa, Sinemet), meperidine (Demerol), extended-release potassium chloride tablets, quinidine (Quinaglute), tranquilizers, and medications for depression and Parkinson’s disease. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had colitis; glaucoma; an enlarged prostate gland; high blood pressure; an overactive thyroid gland; liver, heart, blood vessel, or kidney disease; myasthenia gravis; difficulty urinating; or asthma, bronchitis, emphysema, or lung disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking propantheline, call your doctor.
• talk to your doctor about the risks and benefits of taking propantheline if you are 65 years of age or older. Older adults should not usually take propantheline because it is not as safe or effective as other medications that can be used to treat the same condition.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking propantheline.
• you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
• ask your doctor about the safe use of alcohol while you are taking this medication. Alcohol can make the side effects of propantheline worse.

Propantheline side effects

Propantheline may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• increased sensitivity of your eyes to light
• dizziness
• nervousness
• difficulty sleeping
• headache
• loss of sense of taste
• upset stomach
• vomiting
• bloating
• confusion (especially in the elderly)
• blurred vision
• constipation

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

• fast heartbeat
• heart palpitations
• eye pain
• difficulty urinating
• skin rash
• itching

Propantheline may cause other side effects. Call your doctor if you have any unusual problems while you are taking propantheline.

Solifenacin

Solifenacin is an anticholinergic and antispasmodic agent used to treat urinary incontinence and the overactive bladder syndrome (a condition in which the bladder muscles contract uncontrollably and cause frequent urination, urgent need to urinate, and inability to control urination). Solifenacin was approved for use in the United States in 2004 and it remains in clinical use. Current indications are for treatment of overactive bladder and symptoms of urgency and urinary frequency.

Solifenacin is an anticholinergic agent that inhibits muscarinic actions of acetylcholine on autonomic nerve endings, decreasing secretions and inhibiting gastrointestinal and bladder motility. Solifenacin increases the bladder capacity and decreases contractions and the urgency of urination.

Solifenacin is available in tablets of 5 and 10 mg under the brand name VESIcare. The recommended adult oral dose is 5 to 10 mg once daily.

Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take solifenacin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not split, chew, or crush them. Swallow the tablets with water or another liquid.

Your doctor will probably start you on a low dose of solifenacin and increase your dose later in your treatment.

Solifenacin may help to control your symptoms but will not cure your condition. Continue to take solifenacin even if you feel well. Do not stop taking solifenacin without talking to your doctor.

Solifenacin common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, urinary retention, restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Solifenacin special precautions

Before taking solifenacin:

• tell your doctor and pharmacist if you are allergic to solifenacin, any other medications, or corn.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking. Be sure to mention any of the following: amiodarone (Cordarone, Pacerone); antifungals such as fluconazole (Diflucan), itraconazole (Sporanox), and ketoconazole (Nizoral); carbamazepine (Tegretol); cimetidine (Tagamet); cisapride (Propulsid); clarithromycin (Biaxin); cyclosporine (Neoral, Sandimmune); danazol (Danocrine); delavirdine (Rescriptor); dexamethasone (Decadron); diltiazem (Cardizem, Dilacor, Tiazac); disopyramide (Norpace); dofetilide (Tikosyn); erythromycin (E.E.S., E-Mycin, Erythrocin); ethosuximide (Zarontin); fluoxetine (Prozac, Sarafem); fluvoxamine (Luvox); HIV protease inhibitors such as indinavir (Crixivan) and ritonavir (Norvir); isoniazid (INH, Nydrazid);metronidazole (Flagyl); moxifloxacin (Avelox); nefazodone; phenobarbital (Luminal, Solfoton); phenytoin (Dilantin);pimozide (Orap); procainamide (Procanbid, Pronestyl); quinidine (Quinaglute, Quinidex); rifabutin (Mycobutin); rifampin (Rifadin, Rimactane); sotalol (Betapace); sparfloxacin (Zagam); thioridazine (Mellaril); troglitazone (Rezulin); troleandomycin (TAO); verapamil (Calan, Covera, Isoptin, Verelan); and zafirlukast (Accolate). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor what herbal products you are taking, especially St. John’s wort.
• tell your doctor if you or any of your family members have or have ever had prolonged QT interval (a problem with the way electricity is conducted in the heart that may cause fainting) or unexplained fainting; and if you have or have ever had glaucoma (an eye disease that can cause vision loss); any type of blockage in the bladder or digestive system; difficulty emptying your bladder or a weak urine stream; myasthenia gravis (a disorder of the nervous system that causes muscle weakness); ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum); benign prostatic hypertrophy (BPH, enlargement of the prostate, a male reproductive organ); constipation; or liver or kidney disease.
• tell your doctor if you are pregnant or plan to become pregnant. If you become pregnant while taking solifenacin, call your doctor. Do not take solifenacin while you are breastfeeding.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking solifenacin.
• you should know that solifenacin may cause blurred vision. Do not drive a car or operate machinery until you know how this medication affects you.
• you should know that solifenacin may make it harder for your body to cool down when it gets very hot. Avoid exposure to extreme heat, and call your doctor or get emergency medical treatment if you have fever or other signs of heat stroke such as dizziness, upset stomach, headache, confusion, and fast pulse after you are exposed to heat.

Solifenacin side effects

Solifenacin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• constipation
• stomach pain
• upset stomach
• vomiting
• heartburn
• dry eyes
• blurred vision
• extreme tiredness

Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:

• severe stomach pain
• constipation that lasts longer than 3 days
• painful or frequent urination
• bloody or cloudy urine
• back pain
• swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• hoarseness
• difficulty breathing or swallowing

Solifenacin may cause other side effects. Call your doctor if you have any unusual problems while taking solifenacin.

Symptoms of solifenacin overdose may include:

• flushing
• dry mouth
• dry eyes
• blurred vision
• enlarged pupils (black circle in the middle of the eye)
• confusion
• fever
• fast heartbeat
• shaking hands that you cannot control
• difficulty walking
• hallucinations (seeing things or hearing voices that do not exist)
• coma
• collapse

Tolterodine

Tolterodine is an anticholinergic agent used to treat urinary incontinence and hyperactive bladder syndrome (a condition in which the bladder muscles contract uncontrollably and cause frequent urination, urgent need to urinate, and inability to control urination) to relieve urinary difficulties, including frequent urination and inability to control urination. Tolterodine increases bladder capacity and decreases bladder contractions and the urgency of urination. Tolterodine was approved for use in the United States in 1998 and indications include urge incontinence and overactive bladder syndrome, including symptoms of urinary urgency and frequency. Tolterodine works by relaxing the bladder muscles preventing bladder contraction.

Tolterodine is a synthetic anticholinergic and antispasmotic agent that inhibits muscarinic actions of acetylcholine on autonomic nerve endings, decreasing secretions and inhibiting gastrointestinal and bladder motility.

Tolterodine is available in tablets of 1 and 2 mg and as extended-release (long-acting) capsules of 2 and 4 mg in generic forms and under the brand name Detrol. The recommended adult oral dose is 2 to 4 mg daily. The tablet is usually taken twice a day. The extended-release capsule is usually taken once a day with liquids. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take tolterodine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the extended-release capsules whole; do not split, chew, or crush them.

Tolterodine common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, urinary retention, restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Tolterodine special precautions

Before taking tolterodine:

• tell your doctor and pharmacist if you are allergic to tolterodine or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially clarithromycin (Biaxin), erythromycin (E-mycin, Ery-Tab, others), fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), medications for glaucoma, and vitamins.
• tell your doctor if you have or have ever had kidney or liver disease, glaucoma, or an obstructive gastrointestinal disease, such as pyloric stenosis.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking tolterodine, call your doctor.

Tolterodine side effects

Tolterodine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• blurred vision
• upset stomach
• headache
• constipation
• dry eyes
• dizziness

If you experience any of the following symptoms, call your doctor immediately:

• difficulty urinating
• rash
• chest pain

Trospium

Trospium is an antispasmotic and anticholinergic agent used to treat urinary incontinence and overactive bladder syndrome (a condition in which the bladder muscles contract uncontrollably and cause frequent urination, urgent need to urinate, and inability to control urination). Trospium increases bladder capacity and decreases bladder contractions and the urgency of urination. Trospium was approved for use in the United States in 1975 and indications include urinary urge incontinence and symptoms of overactive bladder such as urinary urgency and frequency.

Trospium is a synthetic anticholinergic agent that inhibits muscarinic (antimuscarinic) actions of acetylcholine on autonomic nerve endings, decreasing secretions and inhibiting gastrointestinal and bladder motility.

Trospium is available in tablets of 20 mg and an extended-release capsule in generic forms and under the brand name Sanctura. The recommended adult oral dose is 20 mg tablet once or twice daily on an empty stomach or 1 hour before meals,or is sometimes taken once a day at bedtime. Trospium extended-release capsule is usually taken once daily in the morning with water on an empty stomach, at least 1 hour before a meal. To help you remember to take trospium, take it around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take trospium exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

Trospium common side effects are those of parasympathetic stimulation and include dryness of the mouth and eyes, decreased sweating, headache, visual blurring, constipation, urinary retention, restlessness, confusion and hallucinations. Anticholinergic agents can precipitate acute narrow angle glaucoma and acute urinary retention.

Trospium special precautions

Before taking trospium:

• tell your doctor and pharmacist if you are allergic to trospium, any other medications, or any of the ingredients in trospium tablets or extended-release capsules. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: antacids; antihistamines; cold medications; ipratropium (Atrovent); medications for depression or mental illness; medications for inflammatory bowel disease or diarrhea, motion sickness, Parkinson’s disease, ulcers, or urinary problems; metformin (Glucophage); morphine (MSIR, Oramorph, others); muscle relaxants; procainamide; tenofovir (Viread); and vancomycin (Vancocin). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had glaucoma (an eye disease that can cause vision loss) or any type of blockage in the bladder or digestive system which causes delays or causes difficulty in emptying your bladder or stomach. Your doctor may tell you not to take trospium.
• tell your doctor if you have or have ever had myasthenia gravis (a disorder of the nervous system that causes muscle weakness); ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum); any disease of the stomach or intestines; frequently occurring constipation; problems emptying your bladder;or benign prostatic hypertrophy (BPH, enlargement of the prostate, a male reproductive organ); or liver or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking trospium, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking trospium.
• you should know that trospium may make you drowsy or dizzy and may cause blurred vision. Do not drive a car or operate machinery until you know how this medication affects you.
• remember that alcohol can add to the drowsiness caused by this medication. You should not drink alcohol within 2 hours of taking trospium.
• you should know that trospium may make it harder for your body to cool down when it gets very hot. Avoid exposure to extreme heat, and call your doctor or get emergency medical treatment if you have fever or other signs of heat stroke such as dizziness, upset stomach, headache, confusion, and fast heartbeat after you are exposed to heat.

Trospium side effects

Trospium may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth, eyes, or nose
• constipation
• headache
• confusion
• gas

Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:

• difficulty urinating
• swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• rash
• hives
• itching
• difficulty breathing or swallowing
• hallucinations (seeing things or hearing voices that do not exist)

Symptoms of trospium overdose may include the following:

• fast heartbeat
• widened pupils (black circle in the middle of the eye)
• sensitivity to light

Antispasmodic drugs for muscle spasm

Muscle relaxers are a heterogeneous group of medications acting both centrally and peripherally to relieve muscle spasms. Muscle relaxers are used to treat two different conditions: (1) spasticity from upper motor neuron syndromes as occurs in multiple sclerosis or cerebral palsy and (2) muscular pain or spasms from peripheral musculoskeletal diseases or injury such as low back pain. Although muscle relaxers have by convention been classified into one group, the Food and Drug Administration (FDA) has approved only a few muscle relaxers in this class for treatment of spasticity; the remainder are approved for treatment of musculoskeletal conditions ⁹.

The muscle relaxers in current use have variable mechanisms of action, efficacy and side effects. Muscle relaxers are generally well tolerated, with the most common side effects being drowsiness and nausea.

Skeletal muscle relaxers have been in wide use for decades. Data from the Third National Health and Nutrition Examination (NHANES III) survey (1988–1994) estimated that 1% of American adults are taking muscle relaxants, often on a chronic basis ¹⁰.

Skeletal muscle relaxers have been approved for either treatment of spasticity or for treatment of musculoskeletal conditions. Drugs classified as skeletal muscle relaxers are baclofen, carisoprodol, chlorzoxazone, cyclobenzaprine, dantrolene, metaxalone, methocarbamol, orphenadrine and tizanidine. Only baclofen, dantrolene, and tizanidine are approved for the treatment of spasticity ⁹. These three antispasticity medications act by different mechanisms: baclofen blocks pre- and post-synaptic GABA-B (gamma-amino butyric acid B) receptors ¹¹, tizanidine is a centrally acting agonist of α2 receptors ¹² and dantrolene directly inhibits muscle contraction by decreasing the release of calcium from skeletal muscle sarcoplasmic reticulum ¹³. Medications from other classes have also been used to treat spasticity. Diazepam, a benzodiazepine, was the first medication thought to be effective for spasticity. It acts by central blockade of GABA-A (gamma-amino butyric acid A) receptors ¹⁴. Other medications used to treat spasticity but not formally approved for this indication include other benzodiazepines, clonidine, gabapentin, and botulinum toxin ¹³.

The skeletal muscle relaxers carisoprodol, chlorzoxazone, cyclobenzaprine, metaxalone, methocarbamol, and orphenadrine have been approved for treatment of musculoskeletal disorders, but not for spasticity. They constitute a heterogeneous group of medications. Cyclobenzaprine is closely related to the tricyclic antidepressants ¹⁵, carisoprodol is metabolized to meprobamate ¹⁶, methocarbamol is structurally related to mephenesin ¹⁵, chlorzoxazone is a benzoxazolone derivative ¹⁷ and orphenadrine is derived from diphenhydramine ¹⁸. The mechanism of action for most of these agents is unclear, but may be related in part to sedative effects. These drugs are often used for treatment of musculoskeletal conditions whether muscle spasm is present or not ¹⁹. Although there is some overlap between clinical usage (tizanidine in particular has been studied for use in patients with musculoskeletal complaints) ²⁰, in clinical practice each skeletal muscle relaxant is used primarily for either spasticity or for musculoskeletal conditions.

List of muscle relaxers

• Baclofen (Lioresal, Baclosan)
• Carisoprodol (Soma, Carisoma, Sodol)
• Chlorzoxazone (Parafon Forte, Remular)
• Cyclobenzaprine (Flexeril)
• Dantrolene (Dantrium)
• Methocarbamol (Marbaxin, Robaxin)
• Metaxalone (Skelaxin)
• Orphenadrine (Flexon, Norgesic, Norflex)
• Tizanidine (Zanaflex)

Baclofen

Baclofen is a centrally acting muscle relaxant commonly prescribed for spasticity in patients with multiple sclerosis. Baclofen is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Baclofen is a gamma-amino butyric acid (GABA) derivative that acts as an agonist of the GABA B receptor, thereby activating potassium channels and reducing calcium conductance leading to hypotonia and muscle relaxation. Baclofen acts primarily at the level of the spinal cord, inhibiting synaptic reflexes. Baclofen reduces the number and severity of muscle spasms and relieves pain, clonus and muscle rigidity due to spasticity. Baclofen is indicated primarily for treatment of spasticity from spinal cord injuries and multiple sclerosis. Baclofen has been used off label as adjunctive therapy to help with alcohol abstinence and withdrawal.

Baclofen was approved for use in the United States in 1977 and is widely used with several million prescriptions filled yearly.

Baclofen is available in various generic forms as well as under the brand names of Lioresal and Remular in tablets of 10 or 20 mg and in formulations for intrathecal injections of 0.5 mg/mL. The recommended adult dose for spasticity is 10 to 20 mg orally three to four times daily at evenly spaced intervals. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take baclofen exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Baclofen must be taken regularly for a few weeks before its full effect is felt. The dose should be increased and tapered gradually.

Continue to take baclofen even if you feel well. Do not stop taking baclofen without talking to your doctor, especially if you have taken large doses for a long time. Your doctor probably will want to decrease your dose gradually.

The most common side effects of baclofen are nausea, drowsiness, confusion, dizziness and fatigue.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Baclofen special precautions

Before taking baclofen:

• tell your doctor and pharmacist if you are allergic to baclofen or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially muscle relaxants, sleeping pills, tranquilizers, and vitamins.
• tell your doctor if you have or have ever had kidney disease, epilepsy, ulcers, a stroke, a rheumatic disease, cerebral palsy, Parkinson’s disease, or a psychiatric condition.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking baclofen, call your doctor immediately.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how baclofen affects you.
• remember that alcohol can add to the drowsiness caused by this drug.

Baclofen side effects

Baclofen may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• dizziness
• weakness
• confusion
• upset stomach

If you experience either of the following symptoms, call your doctor immediately:

• difficulty breathing
• seizures

Baclofen may cause other side effects. Call your doctor if you have any unusual problems while you are taking baclofen.

Carisoprodol

Carisoprodol is a centrally acting muscle relaxant that has been in use for more than fifty years. Carisoprodol is a carbamate derivative similar to meprobamate. Carisoprodol mechanism of action as a muscle relaxant is unknown, but it is a sedative and may act centrally by modifying perception of pain without affecting pain reflexes. Carisoprodol is recommended for treatment of acute, painful disorders caused by strains, sprains, and other muscle injuries and is used with rest, physical therapy, and other measures to relax muscles and relieve pain and discomfort.

Carisoprodol is available by prescription only and is classified as a Schedule IV agent, meaning that it has low potential for abuse and physical or psychological dependence and has an accepted medical usefulness.

Carisoprodol is available in 250 and 350 mg tablets in generic formulations and under the trade names of Soma, Carisoma, Sodol and Vanadom. Fixed combinations of carisoprodol with aspirin or codeine are also available. The recommended adult dosage is 250 to 350 mg three to four times daily for 2 to 3 weeks. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take carisoprodol exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Carisoprodol may cause an upset stomach. Take carisoprodol with food or milk.

Carisoprodol was approved for use in the United States in 1959 and is widely used with more than 10 million prescriptions filled yearly.

Common side effects include dizziness, drowsiness and headache. Overdose can cause progressive obtundation, coma, neuromuscular rigidity, myoclonus and seizures.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Carisoprodol special precautions

Before taking carisoprodol:

• tell your doctor and pharmacist if you are allergic to carisoprodol, meprobamate (Equanil, Meprospan, Miltown, Neuramate), any other medications, or any of the ingredients in carisoprodol tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially medications for allergies, coughs, or colds; muscle relaxants; sedatives; sleeping pills; tranquilizers; and vitamins.
• tell your doctor if you have or have ever had kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking carisoprodol, call your doctor.
• talk to your doctor about the risks and benefits of taking carisoprodol if you are 65 years of age or older. Older adults should not usually take carisoprodol because it is not as safe or effective as other medications that can be used to treat the same condition.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how carisoprodol affects you.
• remember that alcohol can add to the drowsiness caused by this drug.

Carisoprodol side effects

Carisoprodol may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• dizziness
• clumsiness
• headache
• fast heart rate
• upset stomach
• vomiting
• skin rash

If you experience any of the following symptoms, call your doctor immediately:

• difficulty breathing
• fever
• weakness
• burning in the eyes

Carisoprodol may cause other side effects. Call your doctor if you have any unusual problems while you are taking carisoprodol.

Chlorzoxazone

Chlorzoxazone is a centrally acting muscle relaxant commonly used for low back pain caused by muscle strains and sprains. Chlorzoxazone has been linked to rare instances of acute liver injury, a few of which have been fatal. Chlorzoxazone acts centrally rather than directly on muscles to relieve muscle spasms, either through its sedative effects or other unknown mechanisms. Chlorzoxazone is indicated for therapy of low back pain and muscle spasms, in combination with physical therapy, analgesics (such as aspirin or acetaminophen), and rest, although its overall efficacy is considered only fair.

Chlorzoxazone was approved for use in the United States in 1958 and is still widely used.

Chlorzoxazone is available in various generic forms as well as under the brand names of Parafon Forte and Remular in tablets of 250 or 500 mg. The usual recommended dose in adults is 250 to 750 mg orally three to four times daily, reducing the dose to lowest effective level once a response occurs. Chlorzoxazone is typically given for 1 to 4 weeks only. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take chlorzoxazone exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Common side effects of chlorzoxazone include dizziness, drowsiness, headache, fatigue and tremor.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Chlorzoxazone special precautions

Before taking chlorzoxazone:

• tell your doctor and pharmacist if you are allergic to chlorzoxazone or any other medications.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially sedatives, sleeping pills, tranquilizers, and vitamins.
• tell your doctor if you have or have ever had liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking chlorzoxazone, call your doctor.
• talk to your doctor about the risks and benefits of taking chlorzoxazone if you are 65 years of age or older. Older adults should not usually take chlorzoxazone because it is not as safe or effective as other medications) that can be used to treat the same condition.
• you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
• ask your doctor about the safe use of alcohol during your treatment with chlorzoxazone. Alcohol can make the side effects of this medication worse.

Chlorzoxazone side effects

Chlorzoxazone may cause side effects. Your urine may turn purple or red; this effect is not harmful. Tell your doctor if any of these symptoms are severe or do not go away:

• upset stomach
• drowsiness
• dizziness
• lightheadedness
• weakness

If you experience any of the following symptoms, call your doctor immediately:

• skin rash or itching
• yellowing of the skin or eyes
• stomach pain

Chlorzoxazone may cause other side effects. Call your doctor if you have any unusual problems while you are taking chlorzoxazone.

Cyclobenzaprine

Cyclobenzaprine is a centrally acting muscle relaxant closely related to the tricyclic antidepressants. Despite its similarity to tricyclic antidepressants, there is little evidence that cyclobenzaprine causes liver injury. Cyclobenzaprine is a tricyclic antidepressant derivative that relaxes skeletal muscle by an unknown mechanism of action. Cyclobenzaprine is also a central nervous system depressant, and its efficacy may be related to its sedative effects. Cyclobenzaprine is used with rest, physical therapy, and other measures to relax muscles and relieve pain and discomfort caused by strains, sprains, and other muscle injuries.

Cyclobenzaprine comes as a tablet and an extended-release capsule to take by mouth. The recommended dosage in adults is 5 to 10 mg three times daily for 3 to 4 weeks. Cyclobenzaprine is available in tablets of 5 and 10 mg in multiple generic forms and under the trade names of Flexeril, Flexamid and Amrix. Extended release capsules of 15 and 30 mg are also available. The extended-release capsule is usually taken with or without food once a day. Swallow the extended-release capsules whole; do not chew or crush them. If you are not able to swallow the extended-release capsule whole, mix the contents of the capsule with applesauce. Eat the mixture right away and swallow without chewing. After you eat the mixture, take a drink, and swish and swallow to make sure that you have received all the medication.

Cyclobenzaprine is usually administered for limited periods of time. Do not take cyclobenzaprine for more than 3 weeks without talking to your doctor. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take cyclobenzaprine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Cyclobenzaprine was approved for use in the United States in 1977 and it remains widely used with more than 10 million prescriptions filled yearly.

Common side effects include sleepiness, dry mouth, dizziness and headache.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for the missed one.

Cyclobenzaprine special precautions

Before taking cyclobenzaprine:

• tell your doctor and pharmacist if you are allergic to cyclobenzaprine, any other medications, or any of the ingredients in cyclobenzaprine tablets or capsules. Ask your pharmacist for a list of the ingredients.
• tell your doctor if you are taking the following medications or have stopped taking them within the past two weeks: monoamine oxidase (MAO) inhibitors, including isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate). Your doctor will probably tell you not to take cyclobenzaprine if you are taking one of these medications.
• tell your doctor and pharmacist what other prescription and nonprescription drugs, vitamins, nutritional supplements and herbal products you are taking or plan to take. Be sure to mention any of the following: medications for allergies, coughs, or colds; barbiturates such as butabarbital (Butisol), phenobarbital, and secobarbital (Seconal); bupropion (Aplenzin, Forfivo XL, Wellbutrin, Zyban); meperidine (Demerol); sedatives; sleeping pills; selective serotonin reuptake inhibitors (SSRIs) such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac, Sarafem, Selfemra, in Symbyax), fluvoxamine (Luvox), paroxetine (Brisdelle, Paxil, Pexeva), and sertraline (Zoloft); selective serotonin and norepinephrine reuptake inhibitors (SNRIs) such as desvenlafaxine (Khedezla, Pristiq), duloxetine (Cymbalta), levomilnacipran (Fetzima), milnacipran (Savella) and venlafaxine (Effexor); tranquilizers; tricyclic antidepressants (TCAs) such as amitriptyline, amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin (Silenor), imipramine (Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); tramadol (Conzip, Ultram, in Ultracet); verapamil (Calan, Covera HS, Verelan, in Tarka); or any other medication for depression, mood, anxiety, or thought disorder. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with cyclobenzaprine, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
• tell your doctor if you are recovering from a recent heart attack, or if you have an overactive thyroid gland. heart failure (condition in which the heart is unable to pump enough blood to the other parts of the body), or an irregular heartbeat, heart block, or other problems with the electrical impulses of your heart. Your doctor will probably tell you not to take cyclobenzaprine.
• tell your doctor if you have increased pressure in the eye or glaucoma, difficulty urinating, or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking cyclobenzaprine, call your doctor immediately.
• talk to your doctor about the risks and benefits of taking cyclobenzaprine if you are 65 years of age or older. Older adults should not usually take cyclobenzaprine because it is not as safe or effective as other medications that can be used to treat the same condition.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how cyclobenzaprine affects you.
• ask your doctor about the safe use of alcoholic beverages while you are taking cyclobenzaprine. Cyclobenzaprine can make the effects of alcohol worse.

Cyclobenzaprine side effects

Cyclobenzaprine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• dizziness
• nausea
• constipation
• heartburn
• extreme tiredness

If you experience any of the following symptoms, call your doctor immediately:

• skin rash
• hives
• swelling of the face or tongue
• difficulty breathing or swallowing
• irregular or fast heart rate
• chest pain

Cyclobenzaprine may cause other side effects. Call your doctor if you have any unusual problems while you are taking cyclobenzaprine.

Dantrolene

Dantrolene, a muscle relaxant, is used to treat chronic spasticity or muscle spasms associated with spinal cord injuries, stroke, multiple sclerosis, cerebral palsy, or other conditions. Dantrolene differs from other commonly used muscle relaxants in acting peripherally on muscle, rather than centrally on the spinal cord or brain. Dantrolene can cause acute liver injury which can be severe and even fatal (see Important Warning).

Dantrolene is a lipid soluble diphenylhydantoin analogue that inhibits muscle contractions by decreasing the release of calcium from the sarcoplasmic reticulum in target tissue. Dantrolene is used for the treatment of chronic spasticity and treatment for and prophylaxis against malignant hyperthermia (based upon its ability to block calcium release, which is the initiating event in malignant hyperthermia). Dantrolene was approved for use in the United States in 1974 and is still commonly used for spasticity.

Dantrolene is available as capsules of 25, 50 and 100 mg in several generic forms and under the commercial name Dantrium. Dantrolene usually is taken once a day at first and then increased gradually to two to four times a day. In adults, the recommended initial dose for spasticity is 25 mg daily, with subsequent increases to a dose of 25 to 100 mg three times daily. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dantrolene exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. If you cannot swallow capsules, empty the contents into fruit juice and mix well just before taking the dose.

Dantrolene is also available in parenteral formulations for therapy of acute episodes of malignant hyperthermia; the recommended initial dose being 1 mg/kg intravenously. For prophylaxis against hyperthermia, dantrolene is given orally in doses of 4 to 8 mg/kg daily.

Common side effects include weakness, nausea, drowsiness, fatigue and dizziness.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for the missed one.

Dantrolene special precautions

Before taking dantrolene:

• tell your doctor and pharmacist if you are allergic to dantrolene or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially diazepam (Valium); estrogen; medications for seizures, allergies, colds, or coughs; sedatives; sleeping pills; tranquilizers; and vitamins.
• tell your doctor if you have or have ever had liver, heart, rheumatic, or lung disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking dantrolene, call your doctor immediately.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how dantrolene affects you.
• remember that alcohol can add to the drowsiness caused by this drug.
• you should plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Dantrolene may make your skin sensitive to sunlight.

Dantrolene side effects

Dantrolene may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• muscle weakness
• drowsiness
• dizziness
• diarrhea
• fatigue
• difficulty swallowing

In addition to the symptoms mentioned in the IMPORTANT WARNING section, if you experience the following symptom, call your doctor immediately:

• seizures

Dantrolene may cause other side effects. Call your doctor if you have any unusual problems while you are taking dantrolene.

Metaxalone

Metaxalone is a centrally acting skeletal muscle relaxant that has been in use for more than 40 years. Metaxalone acts centrally as a skeletal muscle relaxant, but its efficacy and precise mechanism of action are not well documented. Metaxalone was approved for use in the United States in 1962 and it remains a widely used muscle relaxant. Current indications include the treatment of pain and discomfort from acute musculoskeletal conditions and muscle spasms caused by strains, sprains, and other muscle injuries, in combination with rest, physical therapy, and other measures.

Metaxalone comes as a tablet to take by mouth. The recommended dosage is 800 mg orally three to four times daily. Metaxalone is available by prescription only in 400 and 800 mg tablets in generic forms as well as under the commercial name Skelaxin. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take metaxalone exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Sparse data are available regarding metaxalone safety. Side effects are not common, but can include drowsiness, dizziness, headache, nausea, and dry mouth.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Metaxalone special precautions

Before taking metaxalone:

• tell your doctor and pharmacist if you are allergic to metaxalone, any other medications, or any of the ingredients in metaxalone tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially medications for seizures, allergies, colds, or coughs; pain medications; sedatives; tranquilizers; and vitamins.
• tell your doctor if you have or have ever had kidney disease, liver disease, seizures, or a blood disorder.
• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking metaxalone, call your doctor immediately.
• talk to your doctor about the risks and benefits of taking metaxalone if you are 65 years of age or older. Older adults should not usually take metaxalone because it is not as safe or effective as other medications that can be used to treat the same condition.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how metaxalone affects you.
• remember that alcohol can add to the drowsiness caused by this drug.

Metaxalone side effects

Metaxalone may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• dizziness
• upset stomach
• vomiting
• headache
• nervousness

If you experience any of the following symptoms, call your doctor immediately:

• severe skin rash
• difficulty breathing
• yellowing of the skin or eyes
• unusual bruising or bleeding
• unusual tiredness or weakness
• seizures

Metaxalone may cause other side effects. Call your doctor if you have any unusual problems while you are taking metaxalone.

Methocarbamol

Methocarbamol is a commonly used, centrally acting muscle relaxant. Methocarbamol is a guaifenesin derivative and acts centrally as a muscle relaxant by an unknown mechanism. Methocarbamol was approved for use in the United States in 1957, and currently more than 3 million prescriptions are filled yearly. Methocarbamol is used with rest, physical therapy, and other measures for the relief of acute, painful musculoskeletal conditions caused by strains, sprains, and other muscle injuries.

Methocarbamol comes as a tablet to take by mouth. Methocarbamol is available in 500 and 750 mg tablets in several generic formulations, both alone and in combination with other drugs and under the brand names of Robaxin and Marbaxin. The recommended dosage is 1500 mg orally three to four times daily at first, then it may be changed to three to six times a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take methocarbamol exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

The most common side effects of methocarbamol are drowsiness blurred vision, headache, nausea and skin rash.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Methocarbamol special precautions

Before taking methocarbamol:

• tell your doctor and pharmacist if you are allergic to methocarbamol, any other medications or any of the ingredients in methocarbamol tablets. Ask your doctor or pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: medications for seizures, depression, colds, or coughs; sedatives; and tranquilizers.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking methocarbamol, call your doctor.
• talk to your doctor about the risks and benefits of taking methocarbamol if you are 65 years of age or older. Older adults should not usually take methocarbamol because it is not as safe or as effective as other medications that can be used to treat the same condition.
• you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how methocarbamol affects you.
• talk to your doctor about the safe use of alcohol during your treatment with this medication. Alcohol can make the side effects of methocarbamol worse.

Methocarbamol side effects

Methocarbamol may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• dizziness
• upset stomach
• blurred vision
• fever
• black, blue, or green discoloration of urine

If you experience either of the following symptoms, call your doctor immediately:

• rash
• itching

Methocarbamol may cause other side effects. Call your doctor if you have any unusual problems while you are taking methocarbamol.

Orphenadrine

Orphenadrine is a centrally acting muscle relaxant that works by changing the way your body senses muscle pain. Orphenadrine is a centrally acting, nonopiate analgesic and muscle relaxant that has been in clinical use for more than 50 years. Orphenadrine is a methyl derivative of diphenhydramine (a commonly used antihistamine), but its mechanism of action in causing analgesia and skeletal muscle relaxation is not well defined. Orphenadrine has anticholinergic activity and may act centrally on pain perception. Orphenadrine is currently used with rest, physical therapy, and other measures for the treatment of acute, painful musculoskeletal conditions to relieve pain and discomfort caused by strains, sprains, and other muscle injuries. Orphenadrine can be given orally or parenterally. Orphenadrine was approved for use as a muscle relaxant in the United States in 1957 and it is still in wide use.

Orphenadrine comes as a tablet and an extended-release (long-acting) tablet to take by mouth. Orphenadrine is available in multiple generic forms as standard and extended release tablets of 100 mg. Orphenadrine is also available under commercial names such as Norgesic, Norflex, Deenar, Banflex, Disipal and X-Otag. The recommended dosage is 100 mg twice daily. Try to take orphenadrine at around the same times every day. Orphenadrine extended-release, swallow the extended-release tablets whole, do not split, chew, or crush them. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take orphenadrine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Orphenadrine is also available in parenteral formulations under the names of Flexoject and Myolin. The parenteral dose recommendation is 60 mg either intravenously or intramuscularly twice daily.

The most common side effects are those typical of anticholinergics including drowsiness, dry mouth, diaphoresis, flushing, confusion and visual disturbances. Orphenadrine also has a potential for abuse and fatal overdoses have been reported.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Orphenadrine special precautions

Before taking orphenadrine:

• tell your doctor and pharmacist if you are allergic to orphenadrine,any other medications, or any of the ingredients in orphenadrine tablets or extended-release tablets.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: amantadine (Symadine, Symmetrel), fluphenazine (Prolixin), haloperidol (Haldol), medications for colds or allergies, medications for depression, perphenazine (Trilafon), prochlorperazine (Compazine), promethazine (Phenergan), sedatives, sleeping pills,and trifluoperazine (Stelazine). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had glaucoma; myasthenia gravis; ulcers; a urinary tract or intestinal blockage; an enlarged prostate; an irregular heartbeat; or liver, kidney, or heart disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking orphenadrine, call your doctor.
• talk to your doctor about the risks and benefits of taking orphendrine if you are 65 years of age or older. Older adults should not usually take orphenadrine because it is not as safe as other medications that can be used to treat the same condition.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking orphenadrine.
• you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how orphenadine will affect you.
• ask your doctor about the safe use of alcohol while you are taking this medication. Alcohol can make the side effects of orphenadrine worse.

Orphenadrine side effects

Orphenadrine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth
• drowsiness
• dizziness or lightheadedness
• upset stomach
• vomiting
• constipation
• difficulty urinating
• blurred vision
• headache

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

• fast or irregular heartbeat
• fainting
• confusion
• hallucinations
• skin rash

Orphenadrine may cause other side effects. Call your doctor if you have any unusual problems while you are taking orphenadrine.

Tizanidine

Tizanidine is a commonly used muscle relaxant that has been linked to rare instances of acute liver injury, a few of which have been fatal. Tizanidine is an imidazoline derivative and is a centrally acting muscle relaxant used for therapy of acute muscle spasms and chronic spasticity. The mechanism by which tizanidine causes skeletal muscle relaxation is not well known; it appears to act at the level of spinal cord pain reflexes, most likely through activity as a central alpha-adrenergic agonist which results in an decrease in activity of motor neurons. Tizanidine was approved for use in the United States in 1996 and currently several million prescriptions are filled yearly. The current indications are limited to short-term management of spasticity and increased muscle tone caused by multiple sclerosis (MS, a disease in which the nerves do not function properly and patients may experience weakness, numbness, loss of muscle coordination and problems with vision, speech, and bladder control), stroke, or brain or spinal injury.

Tizanidine comes as a tablet and a capsule to take by mouth. Tizanidine is available in several generic forms as well as under the brand name of Zanaflex in tablets and capsules of 2, 4 or 6 mg. The recommended dose in adults is 2 to 6 mg orally three to four times daily. Tizanidine is usually taken consistently either always with or always without food two or three times a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take tizanidine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Tizanidine capsules may be opened and sprinkled on soft foods such as applesauce. Talk to your doctor before opening the capsules because the effects of the medication when used in this manner may be different than when swallowing the capsule whole.

The medication in the capsule is absorbed differently by the body than the medication in the tablet, so one product cannot be substituted for the other. Each time you have your prescription filled, look at the tablets or capsules in the bottle and make sure that you have received the right product. If you think you received the wrong medication, talk to your doctor or pharmacist right away.

Your doctor will probably start you on a low dose of tizanidine and gradually increase your dose, depending on your response to this medication.

Do not stop taking tizanidine without talking to your doctor. If you suddenly stop taking tizanidine, your heart may beat faster and you may have increased blood pressure or tightness in your muscles. Your doctor will probably decrease your dose gradually.

Common side effects include tiredness, drowsiness, dizziness, muscular weakness, dry mouth and occasionally hypotension.

What should I do if I forget a dose?

If your doctor has told you to take tizanidine regularly, take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Tizanidine special precautions

Before taking tizanidine:

• tell your doctor and pharmacist if you are allergic to tizanidine or any other medications.
• tell your doctor if you are taking ciprofloxacin (Cipro) or fluvoxamine. Your doctor will probably tell you not to take tizanidine if you are taking either of these medications.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: acyclovir (Zovirax); amiodarone (Cordarone, Pacerone); baclofen; cimetidine (Tagamet); clonidine (Catapres, Catapres-TTS); dantrolene (Dantrium); diazepam (Valium); famotidine (Pepcid, Pepcid AC); medications for anxiety, seizures, or high blood pressure; mexiletine (Mexitil); oral contraceptives (birth control pills); propafenone (Rythmol); fluoroquinolones such as gemifloxacin (Factive), levofloxacin (Levaquin), moxifloxacin (Avelox), norfloxacin (Noroxin), and ofloxacin (Floxin); ticlopidine (Ticlid); sedatives; sleeping pills; tranquilizers; verapamil (Calan, Covera, Isoptin, Verelan); and zileuton (Zyflo). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Other medications may also interact with tizanidine, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
• tell your doctor if you have or have ever had kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking tizanidine, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking tizanidine.
• you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
• remember that alcohol can add to the drowsiness caused by this medication.
• you should know that tizanidine may cause dizziness, lightheadedness, and fainting when you get up too quickly from a lying position. This is more common when you first start taking tizanidine. To avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up. Tizanidine can decrease muscle tone, so be careful when walking or doing other activities where you rely on your muscle tone to help with your posture or balance.

Tizanidine side effects

Tizanidine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dizziness
• drowsiness
• weakness
• nervousness
• depression
• vomiting
• tingling sensation in the arms, legs, hands, and feet
• dry mouth
• constipation
• diarrhea
• stomach pain
• heartburn
• increased muscle spasms
• back pain
• rash
• sweating

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• nausea
• extreme tiredness
• unusual bleeding or bruising
• lack of energy
• loss of appetite
• pain in the upper right part of the stomach
• yellowing of the skin or eyes
• unexplained flu-like symptoms
• seeing things or hearing voices that do not exist
• slow heartbeat
• changes in vision

Tizanidine may cause other side effects. Call your doctor if you have any unusual problems while taking tizanidine.

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