What is the recommended approach to reintroducing TB drugs after suspected toxicity?

• A. Rechallenge one drug at a time at a low dose once symptoms have resolved, monitor closely, and adjust regimen
• B. Stop all TB medications permanently
• C. Switch to an entirely new regimen without reintroduction
• D. Double the dose of the suspected drug

Answer: (A)

The main idea here is to manage suspected TB drug toxicity by identifying the culprit without compromising TB treatment. The safest and most effective approach is to temporarily stop all TB medications, then reintroduce each drug one at a time at a low dose after symptoms and any abnormal labs have resolved. You monitor the patient closely for recurrence of symptoms or liver, kidney, or other organ toxicity, and you adjust the regimen based on what is tolerated. If a drug is well tolerated, you continue it at the full dose; if toxicity recurs, that drug is stopped and the regimen is adapted, substituting another drug as needed to complete therapy. This stepwise rechallenge helps pinpoint the offending drug while preserving the chance to complete the TB treatment course safely.

Doubling the dose or switching to an entirely new regimen without reintroduction would raise risk without clarifying which drug is responsible, and permanently stopping all meds would jeopardize TB control.