Experts have designed Anastrozole in order to inhibit an enzyme (a protein) in your body called aromatase. In fact, Aromatase is responsible for helping produce estradiol (a type of estrogen). As a third-generation aromatase inhibitor, anastrozole selectively binds to and reversibly inhibits aromatase, a cytochrome P-450 enzyme complex found in many tissues including those of the premenopausal ovary, liver, and also breast. In fact, aromatase catalyzes the aromatization of androstenedione and testosterone into estrone and estradiol, the final step in estrogen biosynthesis. Lastly, in estrogen-dependent breast cancers, anastrozole may inhibit tumor growth.
When anastrozole inhibits aromatase, less estrogen is produced in the body, and less estrogen is able to bind to the receptors on breast cancer cells. Since certain breast cancer cells need estrogen to grow and divide, aromatase is given to prevent estrogen from being made.
Anastrozole is used with other treatments, such as surgery or radiation, to treat early breast cancer in women who have experienced menopause (change of life or end of monthly menstrual periods). This medication is also used in women, who have experienced menopause, as the first treatment of breast cancer that has spread within the breast or to other areas of the body. This medication is also used to treat breast cancer in women whose breast cancer has worsened after taking tamoxifen (Nolvadex). Also, this can slow or stop the growth of many types of breast cancer cells that need estrogen to grow.
Firstly, Anastrozole comes as a tablet to take by mouth. People usually take it once a day with or without food. In fact, one must take 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. However, take anastrozole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. In fact, you may need to take anastrozole for several years or longer. Continue to take anastrozole even if you feel well. Moreover, do not stop taking anastrozole without talking to your doctor.
Usual starting dose: Anastrozole 1 mg oral tablet by mouth daily.
Anastrozole was associated with less hot flashes, vaginal discharge or vaginal bleeding, stroke, blood clots, and endometrial cancer, compared to tamoxifen. Anastrozole may cause or worsen osteoporosis. It can decrease the density of your bones and increase the chance of broken bones and fractures.
Anastrozole may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- hot flashes
- stomach pain
- loss of appetite
- weight gain
- joint, bone, or muscle pain
- breast pain
- mood changes
- difficulty falling asleep or staying asleep
- 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
- shortness of breath
- difficulty swallowing or breathing
- swelling of the eyes, face, lips, tongue, throat, arms, hands, feet, ankles, or lower legs