Anastrozon® Anastrozole is an antiestrogen drug designed to treat advanced breast cancer in women. Anastrozole is the first drug in the class of third-generation aromatase inhibitors. It works by blocking the aromatase enzyme and subsequently by blocking the production of estrogen in the body. Since many forms of breast cancer cells are stimulated by estrogen, reducing the levels of this hormone in the body can slow the progression of the disease.

Tamoxifen citrate (Nolvadex) is also often used for this purpose, blocking the action of estrogen on the receptors, and not affecting the actual endogenous production of estrogen by the body. Anastrozole has a significant effect on estrogen levels, one daily dose of 1 mg (usually one tablet) causes estrogen suppression in more than 80% of patients. Given the powerful effect of the drug on the hormonal level, it is usually prescribed only to postmenopausal women. During therapy, side effects such as hot flashes and thinning hair may occur, which are much more common in premenopausal patients.

Anastrozole binds reversibly to the aromatase enzyme through competitive inhibition, and inhibits the conversion of androgens to estrogens in peripheral (extragonadal) tissues.