Exemestane is the generic name for the brand-name drug, Aromasin, a synthetic example of one of a class of drugs called aromatase inhibitors.
Exemestane works by binding irreversibly to the bodyís aromastase enzyme, which is responsible for producing estrogen. Many breast cancer cells depend on estrogen to grow and multiply quickly. Once the aromatase inhibitor binds to the aromastase enzyme, the bound aromatase enzyme can no longer produce estrogen. This drug-caused lack of estrogen "starves" estrogen-dependent breast cancer cells, preventing them from multiplying.
Aromatase inhibitors are used to help treat advanced breast cancer. Moreover, if a woman who has had breast cancer has been taking tamoxifen for 5 years, it generally is recommended that she consider taking an aromatase inhibitor.