In pediatric TB, the initial four-drug phase is designed with dosing based on body weight. Which statement is true?

• A. It uses weight-based dosing to adjust the four-drug initial phase
• B. It uses fixed adult dosing
• C. It avoids pyrazinamide
• D. It uses a two-drug regimen

Answer: (A)

Dosing in pediatric TB uses weight-based amounts so each child receives the right drug exposure. Children aren’t just smaller adults—their bodies handle medicines differently at various weights and ages, so giving drugs by mg per kg helps achieve effective levels for isoniazid, rifampin, pyrazinamide, and ethambutol while avoiding too much toxicity. Using fixed adult doses would risk underdosing smaller kids or overdosing larger ones. The initial intensive phase relies on four first-line drugs to prevent resistance and to maximize bacterial kill, and two drugs wouldn’t be enough. Pyrazinamide is included in this phase because it speeds up clearance of the bacilli, shortening therapy and improving outcomes.