## Standard TB Treatment Duration: WHO/RNTCP Regimen **Key Point:** The standard short-course chemotherapy for drug-susceptible TB consists of a 2-month intensive phase followed by a 4-month continuation phase, totaling 6 months. ### Treatment Phases | Phase | Duration | Drugs | Frequency | |-------|----------|-------|----------| | **Intensive** | 2 months | HRZE (Isoniazid, Rifampicin, Pyrazinamide, Ethambutol) | Daily or thrice-weekly | | **Continuation** | 4 months | HR (Isoniazid, Rifampicin) | Daily or thrice-weekly | | **Total** | **6 months** | — | — | **High-Yield:** The 2-4-6 regimen (2 months intensive HRZE + 4 months continuation HR) is the gold standard for drug-susceptible pulmonary and extrapulmonary TB (except CNS TB and disseminated disease). ### Rationale for This Duration 1. **Intensive phase (2 months):** Rapid reduction in bacterial load and infectivity; prevents emergence of drug resistance 2. **Continuation phase (4 months):** Sterilization of lesions and prevention of relapse 3. **Total 6 months:** Balances efficacy (~95% cure rate) with adherence and tolerability **Mnemonic:** **2-4-6 Rule** — 2 months intensive HRZE, 4 months continuation HR, 6 months total. ### Exceptions Requiring Longer Treatment - **CNS TB (meningitis):** 12 months total (2 months HRZE + 10 months HR) - **Disseminated/miliary TB:** 9 months total (2 months HRZE + 7 months HR) - **TB with delayed response:** May extend continuation phase **Clinical Pearl:** Directly observed therapy (DOT) is mandatory for all patients to ensure adherence and prevent drug resistance. In India, RNTCP follows WHO guidelines strictly. [cite:Park 26e Ch 7]
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.