Letrozole is indicated, adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer. Extended adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer who received 5 years of tamoxifen adjuvant therapy. First-time treatment of postmenopausal women with hormone receptor-positive or metastatic breast cancer. Advance breast cancer in postmenopausal women with the disease progression following anti-estrogen. It is a nonsteroidal aromatase inhibitor for adjuvant treatment of hormonally responsive breast cancer. Estrogen is produced by the conversion of androgens through the activity of the aromatase enzyme. Letrozole competitively inhibits the aromatase enzyme system by bidding to the haem group of aromatase, cytochrome P450 Enzyme, which catalyze the conversion of androgens to estrogens, leading to inhibition of the enzyme and significant reduction in plasma estrogens.
Femara should not be used in patients with known or suspected hypersensitivity to Letrozole or anyone with the tablet excipients or other aromatase inhibitors, It is contraindicated during pregnancy, lactation, and in a premenopausal woman. It is also contraindicated in severe hepatic dysfunction.