This is a fixed-dose combination (FDC) of four first-line anti-tubercular drugs, constituting the standard intensive phase regimen for the treatment of newly diagnosed, drug-sensitive pulmonary tuberculosis (TB) in adults as per the Revised National Tuberculosis Control Programme (RNTCP), now known as the National Tuberculosis Elimination Programme (NTEP) in India. It is designed to improve treatment adherence, prevent monotherapy, and reduce the risk of drug resistance.
Adult: One tablet (Isoniazid 300mg + Rifampicin 450mg + Ethambutol 800mg + Pyrazinamide 750mg) once daily, taken on an empty stomach (preferably 1 hour before or 2 hours after food). Duration: 2 months (Intensive Phase).
Note: Take on an empty stomach with a full glass of water to maximize Rifampicin absorption. If gastrointestinal upset occurs, can be taken with a small amount of low-fat food, but this reduces Rifampicin bioavailability. DOSE MUST BE TAKEN UNDER DIRECT OBSERVATION (DOTS) as per NTEP. Do not skip doses. If a dose is missed, take it as soon as remembered, but do not double the dose. Body fluids (urine, sweat, tears) may turn orange-red; this is harmless.
Combination therapy targeting multiple, unique bacterial pathways to achieve rapid bactericidal and sterilizing activity, preventing the emergence of drug-resistant Mycobacterium tuberculosis.
Pregnancy: Category C (US FDA). Use only if clearly needed. Rifampicin is teratogenic in high doses in animals. Isoniazid, Ethambutol, and Pyrazinamide are generally considered safe in pregnancy, but Pyrazinamide use is controversial; WHO recommends it, but some national guidelines (like older Indian RNTCP) avoided it. Current NTEP guidelines INCLUDE Pyrazinamide in pregnancy. Close monitoring is essential. Supplement with Pyridoxine (Vit B6) 25-50 mg/day.
Driving: May cause dizziness, visual disturbances (Ethambutol), or fatigue. Patients should not drive or operate machinery until they know how the medication affects them, especially at the start of therapy.
| Ketoconazole, Itraconazole, Fluconazole | Rifampicin decreases azole levels significantly, leading to therapeutic failure. | Major |
| Oral Contraceptives | Rifampicin reduces efficacy, causing contraceptive failure. Alternative non-hormonal methods required. | Major |
| Warfarin | Rifampicin increases warfarin metabolism, reducing anticoagulant effect. INR monitoring crucial. | Major |
| Antiretroviral Drugs (e.g., Nevirapine, Efavirenz, Protease Inhibitors) | Complex bidirectional interactions. Rifampicin reduces levels of many ARVs. Co-management requires expert guidance and dose adjustments. | Major |
| Phenytoin, Carbamazepine | Rifampicin and Isoniazid can alter levels of these anticonvulsants. Monitor levels closely. | Major |
| Corticosteroids | Rifampicin increases metabolism, reducing steroid effect. | Moderate |
| Digoxin | Rifampicin may decrease digoxin levels. | Moderate |
| Theophylline | Rifampicin increases clearance, reducing effect. | Moderate |
| Acetaminophen (Paracetamol) | Increased risk of hepatotoxicity with Isoniazid. | Moderate |
| Antacids (Aluminum hydroxide) | Reduce absorption of Ethambutol. Administer at least 2 hours apart. | Moderate |
Same composition (Isoniazid (300mg) + Rifampicin (450mg) + Ethambutol (800mg) + Pyrazinamide (750mg)), different brands: