|Synonyms||Estrogen synthesis inhibitors; Estrogen synthase inhibitors; Estrogen blockers|
|Use||Breast cancer, infertility, precocious puberty, medical abortion, gynecomastia, endometriosis, short stature, others|
|Chemical class||Steroidal; Nonsteroidal|
Aromatase inhibitors (AIs) are a class of drugs used in the treatment of breast cancer in postmenopausal women and gynecomastia in men. They may also be used off-label to reduce estrogen conversion when using external testosterone. They may also be used for chemoprevention in high risk women.
Aromatase is the enzyme that catalyzes a key aromatization step in the synthesis of estrogen. It converts the enone ring of androgen precursors such as testosterone, to a phenol, completing the synthesis of estrogen. As hormone positive breast and ovarian cancers require estrogen to grow, AIs are taken to either block the production of estrogen or block the action of estrogen on receptors.