Letrozol Sun (Letrozole)

Letrozole is an aromatase inhibitor used in hormone‑dependent breast cancer therapy.

• Hormone receptor‑positive breast cancer in postmenopausal women: reduces estrogen‑driven tumor growth and delays disease progression.
• Adjuvant treatment of early‑stage disease: improves disease‑free survival after surgery.
• Metastatic breast cancer: helps control tumor spread and prolongs overall survival.

• Letrozole selectively and non‑competitively inhibits the aromatase enzyme, which converts androgens to estrogens in peripheral tissues. By blocking this conversion, systemic estrogen levels fall, depriving estrogen‑dependent tumor cells of a growth stimulus and thereby slowing or halting cancer progression.

Adverse reactions may occur with Letrozol Sun and are categorized by frequency.

Common Side Effects

• Hot flashes: sudden feeling of warmth and sweating.
• Joint and muscle pain: aching in limbs and back.
• Nausea: mild to moderate upset stomach.
• Fatigue: persistent tiredness.
• Headache: mild to moderate intensity.
• Increased sweating: excessive perspiration.

Serious or Rare Side Effects

• Severe liver injury: jaundice, elevated enzymes.
• Bone fracture: increased risk of osteoporosis‑related breaks.
• Pulmonary embolism: sudden shortness of breath and chest pain.
• Allergic reaction: rash, itching, swelling, or anaphylaxis.
• Elevated cholesterol: significant rise in blood lipid levels.

Patients should be counseled on safety measures before starting Letrozol Sun.

• Monitor bone mineral density: assess risk of osteoporosis and consider supplementation.
• Check liver enzymes: perform baseline and periodic hepatic function tests.
• Assess cardiovascular health: evaluate for thrombosis risk factors.
• Contraindicated in pregnancy: avoid use in pregnant women due to teratogenicity.
• Counsel on menopausal symptoms: provide strategies for managing hot flashes and sweating.
• Store at ambient temperature: keep in the original pack, protect from moisture and direct sunlight.

Letrozol Sun may interact with other medicines; interactions are grouped by clinical significance.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): may markedly reduce letrozole exposure.
• Tamoxifen: antagonistic hormonal effects can diminish therapeutic benefit.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., warfarin): may increase bleeding tendency.
• Statins (e.g., simvastatin): potential rise in plasma concentrations.
• Selective serotonin reuptake inhibitors (e.g., fluoxetine): may affect metabolism and plasma levels.