A fixed-dose combination (FDC) of four first-line anti-tubercular drugs used in the intensive phase of treatment for newly diagnosed, drug-sensitive pulmonary and extrapulmonary tuberculosis. This specific strength is designed for patients weighing 30-37 kg, as per the Revised National Tuberculosis Control Programme (RNTCP), now known as the National Tuberculosis Elimination Programme (NTEP), weight-band dosing strategy. It simplifies therapy, improves adherence, and reduces the risk of monotherapy and drug resistance.
Adult: As per NTEP weight bands: This specific 4-drug FDC (H150+R225+E400+Z750) is for patients weighing 30-37 kg. Dose: ONE tablet daily, before breakfast. For other weight bands, different FDC strengths are used.
Note: Take on an empty stomach, at least 1 hour before or 2 hours after food, with a full glass of water. Do not break or crush the FDC tablet unless specified (some are dispersible). Adhere strictly to the daily schedule. If a dose is missed, take it as soon as remembered, but if it's almost time for the next dose, skip the missed dose. Do not double dose.
Combination therapy targeting multiple, distinct biochemical pathways in Mycobacterium tuberculosis to achieve bactericidal and sterilizing effects, preventing emergence of resistance.
Pregnancy: Category C (US FDA). Use only if clearly needed. Rifampicin is teratogenic in animals. Pyrazinamide use in pregnancy is common in WHO/Indian guidelines but debated due to limited safety data. Isoniazid and Ethambutol are considered safer. Benefits of treating active TB outweigh risks. Supplement with Pyridoxine (Vit B6) 25-50 mg/day.
Driving: Generally safe. Caution if dizziness, visual disturbances (Ethambutol), or CNS effects occur.
| Ketoconazole, Itraconazole, Fluconazole | Reduced azole levels due to Rifampicin enzyme induction; treatment failure. | Major |
| Oral Contraceptives, Hormone Replacement Therapy | Reduced efficacy; risk of pregnancy. Use non-hormonal backup. | Major |
| Warfarin, Acenocoumarol | Reduced anticoagulant effect; requires frequent INR monitoring and dose adjustment. | Major |
| Antiretroviral Protease Inhibitors (e.g., Lopinavir/r) & NNRTIs (e.g., Nevirapine) | Complex bidirectional interactions; Rifampicin drastically reduces levels of many ARVs. Requires expert management in HIV-TB coinfection. | Major |
| Phenytoin, Carbamazepine, Valproate | Reduced anticonvulsant levels (Rifampicin); increased Isoniazid levels can inhibit Phenytoin metabolism. Monitor levels. | Major |
| Corticosteroids (e.g., Prednisolone) | Reduced corticosteroid effect due to increased metabolism. | Moderate |
| Digoxin | Reduced Digoxin levels. | Moderate |
| Antacids (Aluminum hydroxide) | Reduced absorption of Ethambutol and possibly others. | Moderate |
| Acetaminophen (Paracetamol) | Increased risk of hepatotoxicity (additive with Isoniazid). | Moderate |
| Alcohol | Increased risk of hepatotoxicity and CNS effects. | Major |
Same composition (Isoniazid (150mg) + Rifampicin (225mg) + Ethambutol (400mg) + Pyrazinamide (750mg)), different brands: