Letrozol Viatris

Letrozole, the active ingredient in Letrozol Viatris, is an aromatase inhibitor presented as a tablet for oral use. It is indicated for hormone receptor‑positive breast cancer in postmenopausal women. GNH USA supplies Letrozol Viatris as a licensed, GDP‑compliant international pharmaceutical supplier serving oncology centres worldwide.

Letrozole is used in the management of hormone‑dependent breast cancer, acting on estrogen synthesis pathways. - Hormone receptor‑positive breast cancer (adjuvant): Reduces risk of disease recurrence after surgery. - Hormone receptor‑positive breast cancer (metastatic): Delays disease progression in advanced disease. - Postmenopausal estrogen‑dependent tumors: Lowers circulating estrogen levels to inhibit tumor growth.

Letrozole may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects: - Hot flashes: Sudden feeling of warmth and sweating. - Arthralgia: Joint pain or stiffness. - Fatigue: Persistent tiredness not relieved by rest. - Nausea: Mild to moderate upset stomach. - Headache: Tension‑type or migraine‑like pain. - Bone loss: Decreased bone mineral density over time.

Serious or Rare Side Effects: - Venous thromboembolism: Deep vein thrombosis or pulmonary embolism. - Severe liver injury: Elevated transaminases or hepatitis. - Cardiovascular events: Myocardial infarction or stroke. - Severe hypersensitivity: Rash, angioedema, or anaphylaxis. - Osteoporotic fracture: Pathologic bone break due to weakened bone.

Before initiating Letrozole therapy, consider the following safety measures. - Cardiovascular assessment: Evaluate history of heart disease or clotting disorders. - Bone health monitoring: Perform baseline bone mineral density testing and consider calcium/vitamin D supplementation. - Liver function: Check hepatic enzymes periodically, especially in patients with pre‑existing liver disease. - Drug interactions: Review concomitant medications that may affect estrogen metabolism. - Pregnancy and lactation: Avoid use in pregnant or breastfeeding women; contraception is required for women of child‑bearing potential. - Store at ambient temperature: Keep below 25°C in the original container, protect from moisture and direct sunlight.

Letrozole can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid): - Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): May reduce Letrozole plasma levels and effectiveness. - Tamoxifen: Concurrent use can antagonize aromatase inhibition and diminish therapeutic benefit.

Moderate Interactions (Monitor Closely): - Anticoagulants (warfarin): May increase bleeding risk; monitor INR. - SSRIs/ SNRIs (e.g., fluoxetine, venlafaxine): Potential to affect hormone metabolism; observe for side‑effect changes. - Cholesterol‑lowering agents (statins): May increase risk of musculoskeletal complaints; assess patient tolerance.