Letronat — Letrozole 2.5 mg Tablets, 30 Tablets

Letronat is supplied as film-coated tablets containing 2.5 mg of letrozole.

Qualitative and Quantitative Composition per Tablet:

• Active Ingredient: Letrozole — 2.5 mg.
• Excipients: Lactose monohydrate, microcrystalline cellulose, maize starch, sodium starch glycolate, magnesium stearate, colloidal silicon dioxide, hypromellose, macrogol, titanium dioxide, approved colorants.

Packaging and Presentation: Round, biconvex, light-yellow to yellow film-coated tablets. 10 tablets per aluminum blister strip. 3 blister strips (total 30 tablets) are packaged in an outer carton displaying Letronat (Letrozole Tablets I.P.) 2.5 mg along with Natco Pharma corporate graphics and official prescribing information.

Pharmacodynamics:
Breast cancer cell proliferation is frequently stimulated by estrogens. In postmenopausal females, the main source of circulating estrogens stems from the conversion of androgens (androstenedione and testosterone) into estrone and estradiol via aromatase in peripheral tissues. Letrozole competitively binds to the heme iron of the aromatase cytochrome P450 subunit, blocking this enzymatic step. This reduces plasma estrogen levels by 98–99%, inhibiting tumor cell growth.

Pharmacokinetics:

• Absorption: Letrozole is rapidly and completely absorbed from the gastrointestinal tract following oral intake. Absolute bioavailability approaches 100%. Food intake does not affect absorption rate or extent.
• Distribution: Plasma protein binding is approximately 60% (primarily albumin). The volume of distribution is large (approx. 1.9 L/kg).
• Metabolism: Extensively metabolized in the liver via cytochrome P450 isoenzymes (primarily CYP3A4 and CYP2A6) into a pharmacologically inactive carbinol metabolite.
• Elimination: Excreted renally as metabolites (~85%) and via feces (~6%). The terminal elimination half-life is approximately 48 hours, supporting stable plasma concentrations with once-daily dosing.

Letronat 2.5 mg is indicated in postmenopausal women for:

• Adjuvant Treatment: Treatment of early hormone-positive breast cancer in postmenopausal women following standard 5-year adjuvant tamoxifen therapy.
• Extended Adjuvant Treatment: Continuation of therapy for early breast cancer following prior adjuvant letrozole treatment.
• First-Line Therapy: Advanced hormone-dependent breast cancer in postmenopausal women.
• Second-Line Therapy: Advanced breast cancer following disease progression on prior anti-estrogen (tamoxifen) therapy.

Letronat 2.5 mg is administered orally once daily at the same time each day.

Administration Instructions: Tablets must be swallowed whole with a sufficient amount of water. Can be taken with or without food.

Duration of Therapy:
For early breast cancer, treatment should continue for 5 years (or until tumor relapse) or as directed by an oncologist. For advanced disease settings, therapy continues until tumor progression is evident.

Administration of Letronat 2.5 mg is contraindicated in:

• Hypersensitivity: Known hypersensitivity to letrozole or any inactive excipient.
• Endocrine Status: Women with premenopausal endocrine status (premenopausal females).
• Pregnancy and Lactation: Strictly contraindicated in pregnant or breastfeeding women.
• Severe Renal Impairment: Creatinine clearance < 10 ml/min (safety not established).
• Severe Hepatic Impairment: Severe hepatic impairment (Child-Pugh Class C).

Clinical interaction studies indicate that clinically significant drug interactions with letrozole are unlikely:

• Metabolic Enzymes: Letrozole is partially metabolized by CYP2A6 and CYP3A4. Potent inducers or inhibitors of these enzymes may theoretically alter clearance, though specific dose adjustments are generally not mandated.
• Concurrent Chemotherapy/Hormone Therapy: Co-administration with tamoxifen or other estrogen-containing therapies should be avoided as they diminish letrozole efficacy.

Pregnancy:
Letronat is contraindicated during pregnancy. Letrozole exposure may cause severe fetal abnormalities. If pregnancy occurs during therapy, treatment must be discontinued immediately.

Lactation:
Excretion into human breast milk is unknown. The drug is contraindicated during lactation.

Adverse reactions are generally mild to moderate and stem from estrogen deprivation pharmacology:

• Nervous System & Psychiatric: Headache, fatigue, dizziness, insomnia, depression, anxiety.
• Musculoskeletal System: Arthralgia (very common), myalgia, limb pain, osteoporosis and increased fracture risk with long-term use, arthritis.
• Vascular & Thermoregulation: Hot flashes, hyperhidrosis, peripheral edema.
• Gastrointestinal Tract: Nausea, vomiting, dyspepsia, constipation, diarrhea, elevated liver enzymes.
• Other: Weight gain, alopecia, skin rash, vaginal bleeding (typically in the first weeks following switch therapy).

Symptoms:
Isolated cases of accidental letrozole overdose have been reported. No specific overdose symptoms have been characterized (single doses up to 30 mg were well tolerated in clinical trials).

Treatment:
No specific antidote exists. Supportive and symptomatic care should be initiated, including gastric lavage (if recent) and vital sign monitoring.

Storage Requirements for Letronat 2.5 mg:

• 🌡️ Temperature Range: Store in a dry, light-protected place at temperatures not exceeding 25–30 °C.
• 💧 Moisture Protection: Keep in original blister packaging to protect tablets from moisture.
• 👶 Safety Precautions: Keep strictly out of reach of children.
• ⏳ Shelf Life: Stated on carton and blisters. Do not use past expiration date. Prescription-only medicine.

To verify authenticity of genuine Letronat 2.5 mg manufactured by Natco Pharma, inspect the following features:

• ✅ Corporate Logo: Distinctive blue-green Natco Pharma corporate logo printed on the outer carton and blister foil.
• ✅ Packaging Markings: Clear factory printing displaying Batch No., Mfg. Date, Exp. Date, and product name Letronat (Letrozole Tablets I.P.) 2.5 mg.
• ✅ Blister Quantity: Standard box contains exactly 3 blister strips of 10 tablets each (total 30 tablets).
• ✅ Print Quality: High-grade packaging artwork without color fading or typography errors.