Letrozol Teva (Letrozole)

Letrozol Teva is an aromatase inhibitor used in the treatment of hormone‑dependent breast cancer.

• Hormone receptor‑positive breast cancer (postmenopausal): reduces estrogen production to slow tumor growth.
• Adjuvant therapy for early‑stage hormone receptor‑positive breast cancer (postmenopausal): helps prevent disease recurrence.
• Advanced or metastatic hormone receptor‑positive breast cancer (postmenopausal): provides disease control when other endocrine therapies are unsuitable.

• Letrozole selectively and non‑steroidally inhibits the aromatase enzyme, which converts androgens to estrogens in peripheral tissues. By blocking this conversion, systemic estrogen levels decline, depriving estrogen‑dependent tumor cells of a growth stimulus and thereby limiting proliferation of hormone receptor‑positive breast cancer cells.

Adverse reactions may occur with letrozole therapy and are categorized by frequency and severity.

Common Side Effects

• Hot flashes: sudden feeling of warmth, often with sweating.
• Joint and muscle pain: aches affecting mobility.
• Fatigue: persistent tiredness not relieved by rest.
• Nausea: mild to moderate upset stomach.
• Headache: tension‑type or throbbing pain.
• Increased sweating: excessive perspiration.

Serious or Rare Side Effects

• Severe liver injury: jaundice, elevated enzymes, hepatic failure.
• Bone fractures: increased risk due to reduced estrogen.
• Pulmonary embolism: sudden shortness of breath, chest pain.
• Severe allergic reactions: rash, swelling, anaphylaxis.
• Elevated cholesterol: significant rise in LDL levels.

Patients should be monitored for specific safety considerations before and during letrozole therapy.

• Bone health monitoring: assess bone mineral density regularly.
• Liver function assessment: perform baseline and periodic liver enzyme tests.
• Cardiovascular risk evaluation: check lipid profile and blood pressure.
• Drug interaction review: verify concomitant medications for potential interactions.
• Pregnancy and lactation warning: avoid use in pregnant or breastfeeding women.
• Store at room temperature: keep in original container, protect from moisture and direct sunlight.

Letrozole may interact with other medicines, influencing its efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce letrozole plasma levels.
• Estrogen‑containing hormone therapy: antagonizes letrozole’s estrogen‑lowering effect.
• Tamoxifen: concurrent use can diminish therapeutic benefit.

Moderate Interactions (Monitor Closely)

• Selective serotonin reuptake inhibitors (SSRIs): may increase risk of bone loss.
• Warfarin: potential alteration of anticoagulant effect, requiring INR monitoring.
• Glucocorticoids: may enhance risk of osteoporosis when combined with letrozole.