What is Anastrozole?

Anastrozole is often indicated as the first course of treatment of postmenopausal women who have hormone receptor-positive as well as hormone receptor unknown locally-advanced or metastatic breast cancer.

Women suffering from advanced breast cancer may also benefit from it, where it also helps postmenopausal women with a disease progression that may be as a result of tamoxifen (Nolvadex) therapy. It works by decreasing the amount of estrogen the body produces. This can slow or stop the growth of many types of breast cancer cells that need estrogen to grow.

Anastrozole may also be used to prevent breast cancer in women who are high risk for developing the disease.

It can also be used in the treatment of excess estrogen production in males. It has been tested for reducing estrogens, including estradiol in men. Excess estradiol can cause benign prostatic hyperplasia, gynecomastia, and symptoms of hypogonadism in males.

The dosage forms for Anastrozole are tablets and capsules. Absolute Pharmacy’s capsules are compounded under the strict USP 795 guidelines. We assure that our preparations are of acceptable strength, quality, and purity with appropriate packaging and labeling in compliance with requirements established by applicable laws and agencies.


Pharmacological Classifications:

Anastrozole is in a class of medications called nonsteroidal aromatase Inhibitors.

Mechanism of Action of Anastrozole:

Anastrozole reversibly binds to the aromatase enzyme, and through competitive inhibition blocks the conversion of androgens to estrogens in peripheral (extra-gonadal) tissues. As a third generation aromatase inhibitor, it selectively binds to and reversibly inhibits aromatase, a cytochrome P-450 enzyme complex found in many tissues.



Anastrozole has excellent oral bioavailability and is widely distributed throughout the body. It is extensively metabolized by the liver, with a half-life of 40-50 hours. It is primarily excreted by the fecal route. Human studies have confirmed that takes two to three hours after the oral administration for anastrozole to reach maximal concentration. Once absorbed, about 40% binds to plasma proteins. The pharmacokinetics of anastrozole is linear and does not change with repeated dosing. Food intake does not seem to affect steady-state serum concentration of the drug.



Before using this medication, tell your doctor your medical history; especially of: liver disease, high blood pressure, heart disease, osteoporosis, or history of blood clots. This medication may cause dizziness. Limit alcoholic beverages.

Do not take this drug if pregnant or breastfeeding. This medication is used mainly in women after menopause. Women of childbearing age should use reliable forms of birth control. If you become pregnant or think you might be pregnant, notify your doctor immediately.


Letrozole/Tamoxifen should not be taken with anastrozole. Estrogen containing therapies should never be used with anastrozole as they diminish pharmacological action. Herbal supplements that have estrogen-like properties should also not be used in conjunction with anastrozole.


Adverse Reactions/Side Effects:

Major side effects with Anastrozole include blurred vision, chest pain, dizziness, headaches, shortness of breath, swelling of feet or lower legs. Check with your doctor immediately if you experience and over the above listed symptoms. Some of the more minor symptoms associated with anastrozole may not need medical attention. These include acid or sour stomach, indigestion, body aches, diarrhea, and heartburn, and hot flashes. Less common (occurring in less than 1 in 10,000) were skin reactions such as lesions, ulcers or blisters. Or allergic reactions with swelling of face, lips tongue or throat.


How is this medicine best taken?

Anastrozole comes in tablet form to be taken orally. This medication can be taken with or without food. If stomach problems develop, take with food. Swallow whole. Do not cut, crush or chew unless otherwise directed. Do not stop taking your medication without consulting your doctor.


What do I do if I miss a dose?:

If you miss a dosage, take the recommended dose as soon as possible. If it is almost time for the next dose, skip the dose you missed. Do not take a double dose.



Keep this medication in it’s original container, tightly closed. Store at room temperature, away from excess heat and humidity. Keep out of reach of children. Dispose expired medication properly.


General Statements:

Do not take medication prescribed for someone else. This medication was compounded specifically for you, do not share medications with anyone else. This patient information contains the most important information about your medication; If you need more information, speak with your healthcare provider.