arimidex

What is Arimidex

Arimidex is a brand name of a drug called anastrozole, which is an nonsteroidal aromatase inhibitor that works by decreasing the amount of estrogen the body makes in postmenopausal women, which may slow the growth of certain types of breast tumors that need estrogen to grow in the body. Arimidex (anastrozole) is used with other treatments, such as surgery or radiation, to treat breast cancer in postmenopausal women. Arimidex is often given to women whose cancer has progressed even after taking tamoxifen (Nolvadex, Soltamox). Arimidex is also used in postmenopausal women, as a first treatment of breast cancer that has spread within the breast or to other areas of the body. Arimidex is available only with your doctor’s prescription.

Arimidex (anastrozole) was approved for use in postmenopausal women with breast cancer in the United States in 1995. Arimidex is a nonsteroidal, specific aromatase inhibitor which has little or no effect on adrenal glucocorticoid or mineralocorticoid synthesis.

Arimidex is a nonsteroidal inhibitor of aromatase, the enzyme responsible for the conversion of testosterone to estrone (E1) and of androstenedione to estradiol (E2). Highest levels of aromatase are found in the ovary and placenta, which are the major sources of estrogen in premenopausal women. However, aromatase is also found in other tissues, such as liver, kidney, adrenals, brain, muscle and subcutaneous fat where it is also active in producing estrogens, although at low levels. These tissues are the major source of estrogen in postmenopausal women. Inhibitors of aromatase were developed to block the synthesis of estrogen in the peripheral tissues and thus, as antiestrogen therapy of estrogen receptor positive breast cancer in postmenopausal women. The aromatase inhibitors in current use include letrozole, exemestane and anastrozole.

Arimidex is available in 1 mg tablets in generic forms and under the brand name Arimidex. Its current indications are as adjuvant therapy in postmenopausal women with hormone responsive breast cancer, as first line therapy of locally invasive or metastatic estrogen receptor positive breast cancer in postmenopausal women, and as adjuvant therapy in postmenopausal women with advanced breast cancer not responsive to tamoxifen.

Arimidex (anastrozole) comes as a tablet to take by mouth. Arimidex (anastrozole) is typically given in single oral doses of 1 mg daily for up to five years. But you may need to take anastrozole for several years or longer. Arimidex (anastrozole) is usually taken once a day with or without food. Take Arimidex (anastrozole) 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 Arimidex (anastrozole) exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Continue to take Arimidex (anastrozole) even if you feel well. Do not stop taking Arimidex (anastrozole) without talking to your doctor.

Common Arimidex (anastrozole) side effects include hot flashes, night sweats, fatigue, dizziness, headache, somnolence, abdominal discomfort, nausea, arthralgias, weight gain and rash. Uncommon, but potentially severe side effects of Arimidex (anastrozole) include decrease in bone mineral density, increase in serum cholesterol and increased rate of cardiovascular events.

Is Arimidex chemotherapy?

No. Chemotherapy means drugs used for cancer treatment. It’s often shortened to “chemo.” Chemotherapy can work throughout the whole body. Chemotherapy kill cancer cells that have spread (metastasized) to parts of the body far away from the original (primary) tumor.

Aromasin vs Arimidex

Aromasin is a brand name of a drug called exemestane. Just like Arimidex (anastrozole), Aromasin (exemestane) is also used to treat early breast cancer in postmenopausal women and who have already been treated with a medication called tamoxifen (Nolvadex) for 2 to 3 years. Aromasin (exemestane) is also used to treat breast cancer in women who have experienced menopause whose breast cancer has worsened while they were taking tamoxifen. Aromasin (exemestane) is in a class of medications called aromatase inhibitors. It works by decreasing the amount of estrogen produced by the body. This can slow or stop the growth of some breast tumors that need estrogen to grow.

Aromasin (exemestane) was approved for use in postmenopausal women with estrogen receptor positive breast cancer in the United States in 1999. Exemestane is available in 25 mg tablets in generic forms and under the brand name Aromasin. Current indications are as adjuvant therapy in postmenopausal women with estrogen sensitive breast cancer after failure, intolerance or as replacement of tamoxifen.

Aromasin (exemestane) is a steroidal inhibitor of aromatase which effectively blocks estrogen synthesis in postmenopausal women and is used as therapy of estrogen receptor positive breast cancer, usually after resection and after failure of tamoxifen. Aromatase is the enzyme responsible for the conversion of testosterone to estrone (E1) and of androstenedione to estradiol (E2). Highest levels of aromatase are found in the ovary and placenta, which are the major sources of estrogen in premenopausal women. However, aromatase is also found in other tissues, such as liver, kidney, adrenals, brain, muscle and subcutaneous fat where it is also active in producing estrogens, although at low levels. These tissues are the major source of estrogen in postmenopausal women. Inhibitors of aromatase were developed to block the synthesis of estrogen in the peripheral tissues and, thus, as antiestrogen therapy of estrogen receptor positive breast cancer in postmenopausal women. Exemestane is a steroidal, specific aromatase inhibitor which has little or no effect on adrenal glucocorticoid or mineralocorticoid synthesis.

Exemestane is given in doses of 25 mg once daily by mouth for up to five years.

Aromasin (exemestane) common side effects include hot flashes, night sweats, arthralgias, fatigue, dizziness, nervousness, insomnia, nausea, weight gain and headache. Uncommon, but potentially severe adverse reactions include reduction in body mineral density and embryo-fetal toxicity.

Arimidex vs Tamoxifen

Tamoxifen is a nonsteroidal antiestrogen that is widely used in the treatment and prevention of breast cancer.

Tamoxifen is selective estrogen receptor modulator (SERM). This means that Tamoxifen acts against (or block) estrogen (a female hormone) in some tissues of the body, but act like estrogen in others. Estrogen can fuel the growth of breast cancer cells. Tamoxifen blocks estrogen in breast cells, which is why Tamoxifen can be useful in lowering breast cancer risk. Other benefits of tamoxifen is the prevention of osteoporosis, a severe weakening of the bones that is more common after menopause.

Tamoxifen is used mainly to treat hormone receptor-positive breast cancer (breast cancer with cells that have estrogen and/or progesterone receptors on them).

To lower the risk of breast cancer, tamoxifen is taken for 5 years. Tamoxifen is taken once a day. Tamoxifen also comes in a liquid form. Tamoxifen can be taken whether or not you have gone through menopause.

The effect of tamoxifen on breast cancer risk has varied in different studies. When the results of all the studies are taken together, the overall reduction in risk for Tamoxifen is about 40% (more than a third). Tamoxifen lowers the risk of both invasive breast cancer and ductal carcinoma in situ (DCIS).

Tamoxifen side effects

Menopausal symptoms

The most common side effects of these tamoxifen are symptoms of menopause. These include hot flashes and night sweats. Tamoxifen can also cause vaginal dryness and vaginal discharge. Pre-menopausal women taking tamoxifen can experience menstrual changes. Menstrual periods can become irregular or even stop. Although periods often start again after the drug is stopped, they don’t always, and some women go into menopause. This is more likely in women who were close to menopause when they started taking the drug.

Other more serious side effects are rare. These include serious blood clots and cancer of the uterus.

Blood clots

Tamoxifen increases your risk of developing blood clots in a vein in your leg (deep venous thrombosis) or in your lungs (pulmonary embolism). These clots can sometimes cause serious problems, and even death. In the major studies looking at tamoxifen for breast cancer prevention, the overall risk of these blood clots over 5 years of treatment was less than 1%. This risk could be higher if you had a serious blood clot in the past, so these drugs are generally not recommended to lower breast cancer risk for anyone with a history of blood clots.

Because tamoxifen increases your risk of developing serious blood clots, there is also concern that it might also increase your risk of heart attack or stroke, although this is not clear. This is something you might want to discuss with your doctor, especially if you have a history of a heart attack or stroke, or if you are at increased risk for them.

Cancer of the uterus

Because tamoxifen acts like estrogen in the uterus, it can increase your risk of endometrial cancer and uterine sarcoma (cancers of the uterus). Tamoxifen also is linked to a higher risk of endometrial pre-cancers.

Although tamoxifen does increase the risk of uterine cancer, the overall increase in risk is low (less than 1%). The risk of uterine cancer goes back to normal within a few years of stopping the drug.

The increased risk seems to affect women over 50, but not younger women.

If you have been diagnosed with uterine cancer or pre-cancer you should not take tamoxifen.

If you have had a hysterectomy (surgery to remove the uterus), you are not at risk for endometrial cancer or uterine sarcoma and do not have to worry about these cancers.

If you are taking tamoxifen, tell your doctor if you have any abnormal vaginal bleeding or spotting, especially after menopause, as these are possible symptoms of uterine cancer.

What is Arimidex used for?

Arimidex (anastrozole) is used to treat early estrogen receptor-positive (or ER+) breast cancer. Arimidex (anastrozole) is also used for first-line treatment of estrogen receptor-positive or estrogen receptor-unknown advanced or metastatic (cancer that has spread) breast cancer. Arimidex (anastrozole) is also used to treat advanced breast cancer that has grown or spread after tamoxifen treatment. Arimidex (anastrozole) is used only in women who have already stopped menstruating (postmenopausal).

Many breast cancer tumors grow in response to estrogen. Arimidex (anastrozole) interferes with the production of estrogen in the body. As a result, the amount of estrogen that the tumor is exposed to is reduced, limiting the growth of the tumor.

Arimidex (anastrozole) is also sometimes used to prevent breast cancer in women who are at high risk of developing the disease. Talk to your doctor about the risks of using Arimidex (anastrozole) for your condition.

Arimidex special precautions

It is very important that your doctor check your progress at regular visits to make sure that Arimidex (anastrozole) is working properly. Blood tests may be needed to check for unwanted effects.

It is unlikely that a postmenopausal woman may become pregnant. But, you should know that using Arimidex (anastrozole) while you are pregnant could harm your unborn baby. Use an effective form of birth control during treatment with Arimidex (anastrozole) and for at least 3 weeks after the last dose. If you think you have become pregnant while using Arimidex (anastrozole), tell your doctor right away.

Do not use Arimidex (anastrozole) together with tamoxifen (Nolvadex®, Soltamox®).

This medicine may cause serious allergic reactions, including anaphylaxis and angioedema, which can be life-threatening and require immediate medical attention. Call your doctor right away if you have itching, hives, hoarseness, trouble breathing or swallowing, or any swelling of your hands, face, or mouth while you are using Arimidex (anastrozole).

Check with your doctor right away if you start having chest pains or difficulty with breathing. This medicine may increase the chance of heart problems, including heart attack, in women who have a history of ischemic heart disease.

This medicine may decrease bone mineral density when used for a long time. A low bone mineral density can cause weak bones or osteoporosis. If you have any questions about this, talk to your doctor.

This medicine may increase your cholesterol or fat in the blood. If this happens, your doctor may give you medicine to lower the cholesterol and fat.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, and herbal or vitamin supplements.

Before taking Arimidex (anastrozole):

  • tell your doctor and pharmacist if you are allergic to anastrozole, or any other medications, or any of the ingredients in Arimidex (anastrozole). 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: medications that contain estrogen such as hormone replacement therapy (HRT) and hormonal contraceptives (birth control pills, patches, rings, and injections); raloxifene (Evista); and tamoxifen (Nolvadex). 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 high cholesterol, osteoporosis (condition in which the bones are fragile and break easily), liver, or heart disease.
  • you should know that Arimidex (anastrozole) should only be taken by women who have undergone menopause and cannot become pregnant. However, if you are pregnant or breast-feeding, you should tell your doctor before you begin taking this medication. Arimidex (anastrozole) may harm the fetus.
  • Safety and efficacy of Arimidex (anastrozole) have not been established in patients younger than 18 years.
  • Premenopausal women (still having menstrual cycles)— Arimidex (anastrozole) should not be used in these patients.

Arimidex interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Bone problems (e.g., osteoporosis) or
  • Hypercholesterolemia (high cholesterol or fat in the blood) or
  • Ischemic heart disease (e.g., heart attack, angina), history of, or
  • Liver disease—Use with caution. May make these conditions worse.

Arimidex dosage

Take Arimidex (anastrozole) only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance for side effects.

Arimidex (anastrozole) comes with a patient information leaflet. Read and follow these instructions carefully. Ask your doctor if you have any questions.

You may take Arimidex (anastrozole) with or without food.

Arimidex (anastrozole) sometimes causes nausea, vomiting, or diarrhea. However, it is very important that you continue to use the medicine, even if you begin to feel ill. Ask your doctor for ways to prevent these effects or make them less severe.

The dose of this medicine will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
  • For breast cancer:
    • Adults—1 milligram (mg) once a day.
    • Children—Use and dose must be determined by your doctor.

Adult dose for breast cancer

  • Initial dose: 1 mg orally taken once a day
  • Duration of therapy: Until tumor progression (treatment of advanced breast cancer); unknown (adjuvant treatment of early breast cancer)

Uses:

  • Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer;
  • First-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor unknown locally advanced or metastatic breast cancer;
  • Second-line treatment of advanced breast cancer in postmenopausal women with disease progression following tamoxifen therapy.

Renal dose adjustments

  • No adjustment recommended.

Dialysis

  • Data not available.

Liver dose adjustments

  • Mild to Moderate Hepatic Impairment: No adjustment recommended.
  • Stable Hepatic Cirrhosis: No adjustment recommended.
  • Severe Hepatic Impairment: Data not available.

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.

Arimidex side effects

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

  • weakness
  • headache
  • hot flashes
  • sweating
  • stomach pain
  • nausea
  • vomiting
  • loss of appetite
  • constipation
  • diarrhea
  • heartburn
  • weight gain
  • joint, bone, or muscle pain
  • breast pain
  • mood changes
  • depression
  • difficulty falling asleep or staying asleep
  • nervousness
  • dizziness
  • vaginal bleeding
  • vaginal dryness or irritation
  • pain, burning, or tingling in the hands or feet
  • dry mouth
  • hair thinning

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

  • chest pain
  • sore throat, cough, fever, chills, swollen glands, or other signs of infection
  • swelling, redness, or warmth in hand or arm
  • difficult, painful, or urgent urination
  • blurred vision or vision changes
  • yellowing of the skin or eyes
  • pain in the upper right part of the stomach
  • skin lesions, ulcers, or blisters
  • rash
  • hives
  • itching
  • shortness of breath
  • difficulty swallowing or breathing
  • swelling of the eyes, face, lips, tongue, throat, arms, hands, feet, ankles, or lower legs

Arimidex (anastrozole) may cause or worsen osteoporosis. It can decrease the density of your bones and increase the chance of broken bones and fractures. Talk to your doctor about the risks of taking this medication and to find out what you can do to decrease these risks.

Arimidex (anastrozole) more common side effects:

  • blurred vision
  • bone pain
  • chest pain or discomfort
  • dizziness
  • headache
  • nervousness
  • pounding in the ears
  • slow or fast heartbeat
  • swelling of the feet or lower legs

Arimidex (anastrozole) less common side effects:

  • arm, back, or jaw pain
  • chest tightness or heaviness
  • chills
  • cough
  • cough producing mucus
  • difficult or painful urination
  • difficulty breathing
  • dizziness, severe
  • fever
  • headache, continuing
  • hoarseness
  • increased blood pressure
  • lower back or side pain
  • nausea
  • pain, tenderness, bluish color, or swelling of the foot or leg
  • sore throat
  • sweating
  • unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
  • vaginal bleeding (unexpected and heavy)

Incidence not known:

  • blistering, peeling, or loosening of the skin
  • confusion
  • constipation
  • dark urine
  • depression
  • diarrhea
  • difficulty swallowing
  • dry mouth
  • general tiredness and weakness
  • hives or welts, itching, skin rash
  • incoherent speech
  • increased urination
  • joint or muscle pain
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
  • light-colored stools
  • loss of appetite
  • metallic taste
  • muscle weakness
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • sores, ulcers, or white spots in the mouth or on the lips
  • stomach pain
  • thirst
  • upper right abdominal pain
  • vomiting
  • weight loss
  • yellow eyes and skin

Arimidex (anastrozole) may cause other side effects. Call your doctor if you have any unusual problems while taking Arimidex (anastrozole).