AROMATASE INHIBITORS

AROMATIZATION

INDRODUCTION Aromatization: Aromatase is a enzyme It converts androgens into estrogen Aromatase Inhibitors: Block the production of E

CLASSIFICATION OF AIs 2 TYPES 1- IRREVERSIBLE STEROIDAL INHIBITORS: Exemestane It forms a permanent and deactivating bond with the aromatase enzyme 2- REVERSIBLE NON-STEROIDAL INHIBITORS: Anastrozole Letrozole Inhibit the synthesis of E via reversible competition for the aromatase enzyme

MECHANISM OF ACTION SOURCE OF ESTROGEN: In premenopausal women: Main source is ovaries In post-menopausal women: E is produced in peripheral tissues 

AROMATASE & GYNECOMASTIA Excess aromatization in the presence of high testosterone levels in males: GYNECOMASTIA CLINICAL RELEVANCE: So AIs can be used for the treatment of

SIDE EFFECTS OF AIs BONE: Osteoporosis, arthritis, joint & bone pain Hot flushes Endometrial cancer: No increased risk Thromboembolism:

USES OF AIs Treatment of breast & ovarian cancer in postmenopausal women Tamoxifen resistant breast carcinoma Gynecomastia in men