A 35-year-old man with newly diagnosed sputum-positive pulmonary tuberculosis (Category 1) has completed 2 months of intensive phase therapy (HRZE) under RNTCP. He is asymptomatic, chest X-ray shows partial resolution of infiltrates, and sputum microscopy is now negative. What is the next step in management?

## Standard RNTCP TB Treatment Regimen **Key Point:** The standard Category 1 (new sputum-positive TB) regimen under RNTCP consists of: - **Intensive phase:** 2 months of HRZE (Isoniazid, Rifampicin, Pyrazinamide, Ethambutol) - **Continuation phase:** 4 months of HR (Isoniazid, Rifampicin) ## Clinical Assessment at End of Intensive Phase After 2 months of HRZE: - Sputum conversion (negative sputum smear) is the key indicator of treatment response - Symptomatic improvement and radiological improvement are supportive but not diagnostic - A sputum-negative patient at the end of intensive phase should proceed to continuation phase **High-Yield:** Continuation phase with HR for 4 months is the standard next step for sputum-negative patients after successful intensive phase. This ensures completion of the full 6-month regimen and reduces relapse rates. ## Why This Patient Needs Continuation Phase | Finding | Interpretation | |---------|----------------| | Sputum negative after 2 months | Excellent response; proceed to continuation | | Asymptomatic | Confirms clinical improvement | | Partial radiological improvement | Expected at this stage; complete resolution takes longer | | No mention of adverse effects | No reason to alter regimen | **Clinical Pearl:** Sputum conversion by end of intensive phase predicts treatment success and low relapse risk. Patients who remain sputum-positive after 2 months require investigation for drug resistance or non-adherence. **Mnemonic — RNTCP Category 1 Regimen:** "2-4 Rule" = 2 months intensive (HRZE) + 4 months continuation (HR) = 6 months total. [cite:Park 26e Ch 8 — RNTCP Guidelines]