A first-line, fixed-dose combination (FDC) anti-tubercular therapy (ATT) used in the intensive phase of treatment for drug-susceptible pulmonary and extrapulmonary tuberculosis. This specific strength is designed for patients weighing 30-37 kg, aligning with WHO weight-band dosing recommendations. It is a cornerstone of India's Revised National Tuberculosis Control Programme (RNTCP), now NTEP (National Tuberculosis Elimination Programme), to improve adherence and prevent monotherapy.
Adult: This specific FDC (75/150/275/400 mg) is for patients weighing 30-37 kg. Standard NTEP weight-band dosing: 25-39 kg: 2 tablets; 40-54 kg: 3 tablets; 55-69 kg: 4 tablets; ≥70 kg: 5 tablets. All doses are once daily.
Note: Take all tablets as a single daily dose, on an empty stomach (at least 1 hour before or 2 hours after food), preferably in the morning. Swallow whole with water. Do not crush or chew. Adhere strictly to DOT (Directly Observed Treatment) under NTEP.
Combination therapy targeting multiple, distinct pathways in Mycobacterium tuberculosis to achieve rapid bactericidal and sterilizing activity, preventing emergence of resistance.
Pregnancy: Pregnancy Category C (US FDA). Use only if clearly needed. Isoniazid, Rifampicin, Ethambutol are considered relatively safe. Pyrazinamide is included in WHO guidelines but used with caution in India; often omitted in some regimens. Supplement with Pyridoxine (Vit B6) 25-50 mg/day.
Driving: Caution advised. May cause dizziness, visual disturbances (Ethambutol), or peripheral neuropathy, impairing ability to drive or operate machinery.
| Ketoconazole, Itraconazole, Fluconazole | Reduced azole levels due to Rifampicin induction. | Major |
| Oral Contraceptives | Reduced efficacy, leading to contraceptive failure. | Major |
| Warfarin | Reduced anticoagulant effect. | Major |
| Antiretroviral Protease Inhibitors (e.g., Lopinavir, Atazanavir) | Markedly reduced ARV levels; contraindicated. | Contraindicated |
| NNRTIs (e.g., Nevirapine, Efavirenz) | Complex bidirectional interactions; dose adjustment needed. | Major |
| Phenytoin, Carbamazepine | Reduced anticonvulsant levels; increased Isoniazid toxicity risk. | Major |
| Corticosteroids | Reduced steroid efficacy. | Moderate |
| Theophylline | Reduced theophylline levels. | Moderate |
| Cyclosporine, Tacrolimus | Reduced immunosuppressant levels, risking graft rejection. | Major |
| Acetaminophen (Paracetamol) | Increased risk of hepatotoxicity (with Isoniazid). | Moderate |
Same composition (Isoniazid (75mg) + Rifampicin (150mg) + Ethambutol (275mg) + Pyrazinamide (400mg)), different brands: