A 42-year-old female from Mumbai with newly diagnosed pulmonary TB (sputum smear-positive) is enrolled in RNTCP. She is on standard 4-drug therapy (HRZE) and completes 2 months of intensive phase. At the start of continuation phase, she develops jaundice, elevated transaminases (ALT 280 U/L, AST 320 U/L), and total bilirubin 4.2 mg/dL. Hepatitis A and B serology are negative. What is the most appropriate next step in TB management according to RNTCP guidelines?