Isoniazid |
5 mg/kg/day (max 300 mg/day) |
6–18 months |
Inhibits mycolic acid synthesis, essential for cell wall |
Highly potent, good penetration into tissues |
Hepatotoxicity, Peripheral neuropathy |
Rifampicin |
10–20 mg/kg/day (max 600 mg/day) |
6–18 months |
Inhibits DNA-dependent RNA polymerase, blocking RNA synthesis |
Broad activity, reduces treatment duration |
Hepatotoxicity, Drug interactions |
Pyrazinamide |
15–30 mg/kg/day (max 2 g/day) |
Initial 2 months |
Effective in acidic pH, disrupts mycobacterial cell membrane |
Effective against latent TB |
Hepatotoxicity, Hyperuricemia |
Ethambutol |
15–25 mg/kg/day |
Initial 2 months |
Inhibits arabinose transferase, affecting cell wall biosynthesis |
Prevents resistance emergence |
Optic neuritis, Visual disturbances |