Letrozol Stada (Letrozole)

Letrozole is an aromatase inhibitor used in the management of hormone‑dependent breast cancer.

• Hormone‑receptor‑positive breast cancer in postmenopausal women: reduces estrogen production to slow tumor growth.
• Adjuvant therapy after surgery: helps prevent cancer recurrence by maintaining low estrogen levels.
• Metastatic breast cancer in postmenopausal patients: provides disease control when cancer has spread.
• Neoadjuvant therapy before surgery: shrinks tumors to allow less extensive surgical procedures.
• Combination therapy with tamoxifen or ovarian suppression: enhances overall anti‑estrogen effect.

• Letrozole reversibly binds to the aromatase enzyme, inhibiting its activity. By blocking the conversion of androgens to estrogens, it markedly lowers circulating estrogen levels, which deprives estrogen‑dependent breast cancer cells of a growth stimulus, thereby slowing tumor proliferation.

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

Common Side Effects

• Hot flashes: transient episodes of warmth and sweating.
• Arthralgia: joint pain or stiffness.
• Fatigue: persistent tiredness.
• Nausea: mild to moderate upset stomach.
• Headache: occasional dull or throbbing pain.
• Increased cholesterol: modest rise in blood lipid levels.

Serious or Rare Side Effects

• Osteoporosis: reduced bone mineral density leading to fractures.
• Severe liver injury: marked elevation of liver enzymes or hepatic failure.
• Deep vein thrombosis: clot formation in deep veins, potentially leading to pulmonary embolism.
• Cardiovascular events: increased risk of heart attack or stroke.
• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Vision changes: blurred vision or ocular discomfort.

Before initiating Letrozole therapy, several safety considerations should be reviewed.

• Pregnancy contraindication: drug is classified as Category X and must not be used during pregnancy.
• Breastfeeding restriction: not recommended for nursing mothers as it may affect milk production.
• Bone health monitoring: assess baseline bone density and consider calcium/vitamin D supplementation.
• Cardiovascular risk assessment: evaluate history of heart disease or stroke before treatment.
• Liver function testing: perform baseline hepatic enzymes and monitor periodically.
• Store at below 25°C: keep tablets in the original container, protect from moisture and direct sunlight.

Letrozole can interact with several medicines, influencing its effectiveness or safety profile.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampicin, carbamazepine): may markedly reduce letrozole plasma concentrations.
• Estrogen‑containing hormone therapy: antagonizes the anti‑estrogen effect of letrozole.

Moderate Interactions (Monitor Closely)

• Antifungal azoles (e.g., ketoconazole, itraconazole): can increase letrozole levels, requiring dose observation.
• Warfarin: may enhance anticoagulant effect, necessitating INR monitoring.
• Selective serotonin reuptake inhibitors (SSRIs): potential for modest pharmacokinetic interaction.
• Cholesterol‑lowering statins: occasional effect on metabolism, watch for muscle symptoms.
• Calcium supplements with high doses of vitamin D: may affect absorption, advise timing separation.