Letrozole Tablet 2.5 mg is a widely used medication, primarily for the treatment of breast cancer in postmenopausal women. Here’s a comprehensive overview:
What it is:
- Letrozole is an aromatase inhibitor.
- It works by decreasing the amount of estrogen hormone your body makes. Estrogen can stimulate the growth of certain types of breast cancer (hormone-receptor-positive breast cancer), so by lowering estrogen levels, letrozole helps slow or stop the cancer cells from growing and spreading.
- It is typically used in postmenopausal women because, after menopause, the ovaries no longer produce estrogen. Instead, a small amount of estrogen is produced in other tissues (like fat, muscle, and skin) by an enzyme called aromatase. Letrozole specifically blocks this enzyme.
- The brand name for letrozole is often Femara®.
Uses:
- Adjuvant treatment of early breast cancer: For postmenopausal women with hormone receptor-positive early breast cancer.
- Extended adjuvant treatment of early breast cancer: For postmenopausal women who have received prior standard adjuvant tamoxifen therapy for 5 years.
- First-line treatment of advanced breast cancer: In postmenopausal women with hormone receptor-positive or unknown locally advanced or metastatic breast cancer.1
- Second-line treatment of advanced breast cancer: In postmenopausal women with disease progression following antiestrogen therapy2.
- Ovulation induction: It’s also used off-label by fertility doctors to induce ovulation, often with fewer side effects than clomiphene. However, its use for infertility was banned in India in 2011.
Important Considerations & Side Effects:
- Postmenopausal women only: Letrozole is effective primarily in postmenopausal women. It is contraindicated in premenopausal women and during pregnancy.
- Pregnancy and Breastfeeding: Letrozole can cause fetal harm and is contraindicated in pregnant women. Women of reproductive potential should use effective contraception during treatment and for at least 3 weeks after the last dose. It is not known if it passes into breast milk, so breastfeeding is not recommended.
- Drug Interactions: Letrozole can interact with other medications, including estrogens (like hormone replacement therapy or birth control pills) and tamoxifen. Always inform your doctor about all medications, supplements, and herbal products you are taking.
- Monitoring: Your doctor will likely monitor your cholesterol levels and bone mineral density regularly during treatment.
Mechanism of Action:
- Letrozole is a non-steroidal aromatase inhibitor.
- It selectively and competitively inhibits the enzyme aromatase, which is responsible for the conversion of androgens (male hormones) into estrogens (female hormones) in peripheral tissues (e.g., fat, muscle).
- By blocking aromatase, letrozole significantly lowers systemic estrogen levels, thereby depriving hormone-receptor-positive breast cancer cells of the estrogen they need to grow.