Capnat 500 — Capecitabine 500 mg Tablets, 10 Tablets

Capnat 500 is supplied as film-coated tablets containing 500 mg of capecitabine.

Qualitative and Quantitative Composition per Tablet:

• Active Ingredient: Capecitabine — 500 mg.
• Excipients: Lactose monohydrate, croscarmellose sodium, hypromellose, microcrystalline cellulose, magnesium stearate, titanium dioxide, iron oxide red/yellow.

Pharmacodynamics:
Capecitabine is an orally administered fluoropyrimidine carbamate acting as a tumor-activated cytostatic agent. It undergoes a three-step enzymatic cascade. The final step occurs within tumor tissue, where thymidine phosphorylase (TP) converts capecitabine into 5-fluorouracil (5-FU). 5-FU inhibits thymidylate synthase, disrupting DNA replication and cell division.

Pharmacokinetics:

• Absorption: Rapidly and completely absorbed from the gastrointestinal tract. Food intake decreases absorption rate but has minimal impact on the area under the curve (AUC) of the active metabolite.
• Distribution: Plasma protein binding (primarily albumin) is approximately 60%.
• Metabolism: Metabolized in the liver by carboxylesterase to 5'-deoxy-5-fluorocytidine (5'-DFCR), then converted by cytidine deaminase in the liver and tumor to 5'-deoxy-5-fluorouridine (5'-DFUR), which is transformed into 5-FU by TP.
• Elimination: Terminal elimination half-life is approximately 45 to 60 minutes. Excreted predominantly renally (~95.5%) as metabolites.

Capnat 500 is indicated in adult patients for:

• Colorectal Cancer: Adjuvant treatment of stage III colon cancer; first-line and subsequent treatment of metastatic colorectal cancer.
• Breast Cancer: In combination with docetaxel for locally advanced or metastatic breast cancer following failure of anthracycline-containing chemotherapy; as monotherapy following failure of taxane and anthracycline regimens.
• Gastric Cancer: First-line treatment of advanced gastric cancer in combination with platinum-based regimens.

Capnat 500 is taken orally within 30 minutes after a meal with water.

Dosing Regimen:

• Standard Dose: Typically 1250 mg/m2 administered twice daily (morning and evening) for 2 weeks followed by a 7-day rest period (21-day treatment cycle).
• Combination Therapy: Dosages may be adjusted based on specific clinical protocols (e.g., 800–1000 mg/m2 twice daily).
• Administration Instructions: Swallow tablets whole without chewing or crushing. Do not double doses if a tablet is missed.

Administration of Capnat 500 is contraindicated in:

• Hypersensitivity: Known hypersensitivity to capecitabine or any excipient, or known hypersensitivity to 5-fluorouracil.
• DPD Deficiency: Known complete absence of dihydropyrimidine dehydrogenase (DPD) activity.
• Severe Renal Impairment: Creatinine clearance < 30 ml/min.
• Hematologic Contraindications: Severe baseline leukopenia, neutropenia, or thrombocytopenia.
• Pregnancy and Lactation: Strictly contraindicated in pregnant or breastfeeding women.
• Concurrent Medications: Concomitant treatment with sorivudine or its chemically related analogues (e.g., brivudine).

Evaluated drug interactions for Capnat include:

• Coumarin Anticoagulants: Capecitabine significantly alters warfarin pharmacokinetics, potentially leading to severe hemorrhage. Regular INR monitoring is mandatory.
• Phenytoin: Potential elevation of plasma phenytoin concentrations leading to toxicity symptoms.
• Antacids: Aluminum and magnesium hydroxide-containing antacids slightly increase capecitabine absorption.
• Radiation and Cytotoxic Agents: Compound overall myelosuppressive toxicity.

Pregnancy:
Capnat 500 is contraindicated during pregnancy due to teratogenic and embryotoxic risks. Patients of childbearing potential must use effective contraception during treatment and for several months post-therapy.

Lactation:
Excretion into human breast milk is unknown; however, due to potential adverse effects, breastfeeding must be discontinued during therapy.

The most frequent and clinically significant adverse reactions associated with capecitabine include:

• Hand-Foot Syndrome (Palmar-Plantar Erythrodysesthesia — Very Common): Numbness, dysesthesia, tingling, pain, swelling, erythema, sloughing, and blistering of palms and soles.
• Gastrointestinal Tract: Diarrhea (can be severe), nausea, vomiting, stomatitis, abdominal pain, constipation, anorexia.
• Hematologic Toxicity: Anemia, neutropenia, thrombocytopenia, leukopenia.
• Skin & Appendages: Dermatitis, dry skin, alopecia, pruritus.
• General Disorders: Fatigue, asthenia, pyrexia, limb pain.

Symptoms:
Acute overdose manifests as nausea, vomiting, diarrhea, mucositis, gastrointestinal bleeding, and bone marrow suppression (myelosuppression).

Treatment:
No specific antidote exists. Supportive and symptomatic management should be administered to correct gastrointestinal and hematological complications and prevent infections.

Storage Requirements for Capnat 500:

• 🌡️ Temperature Control: Store in a dry place at temperatures not exceeding 25–30 °C.
• 💧 Moisture Protection: Keep in original 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 the authenticity of genuine Capnat 500 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 designation Capnat 500 (Capecitabine Tablets I.P.).
• ✅ Print Quality: High-grade packaging artwork without color fading or typography errors.