Treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy.

Exemestane is an irreversible, steroidal aromatase inactivator. It prevents conversion of androgens to estrogens by tying up the enzyme aromatase. In breast cancers where growth is estrogen-dependent, this medicine will lower circulating estrogens.

Bioavailability is 42%; following a high-fat breakfast, exemestane plasma levels increased by about 40%, extensively metabolized by CYP3A4 , protein binding: 90%, elimination half-life: 24 hours, excretion：urine (42% as metabolites), feces (42%).

Hypersensitivity to exemestane or any component of the formulation, premenopausal women, pregnancy, lactation.

Fetal risk has been demonstrated.

Avoided

Fatigue (22%), nausea (18%), pain (13%), depression (13%), hot flashes (13%), insomnia (11%), anxiety (10%), dyspnea (10%), dizziness (8%), headache (8%), vomiting (7%), abdominal pain (6%), anorexia (6%), influenza-like symptoms (6%), cough (6%), constipation (5%), fever (5%).

25 mg once daily after a meal, dosage adjustment with CYP3A4 inducers: 50 mg once daily when used with potent inducers (e.g., rifampin, phenytoin).