Tuberculosis — SCE Infectious Diseases MCQ

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ModerateTuberculosisTuberculosisSCE Infectious Diseases

A 62-year-old man is being treated for pulmonary TB. At week 3, routine liver function tests show ALT 520 U/L (normal <40) and bilirubin 68 µmol/L. He is asymptomatic. What is the most appropriate immediate action?

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Correct answer: E — Stop all hepatotoxic anti-TB drugs (Isoniazid, Rifampicin, Pyrazinamide) and monitor LFTs

Drug-induced liver injury (DILI) is defined as ALT >5× ULN (asymptomatic) or >3× ULN with symptoms/jaundice. This patient has ALT >10× ULN with jaundice. All potentially hepatotoxic anti-TB drugs (Isoniazid, Rifampicin, Pyrazinamide) must be stopped immediately. Once LFTs normalise, drugs are reintroduced sequentially: Rifampicin first, then Isoniazid (the two most effective drugs), monitoring LFTs between each reintroduction. Pyrazinamide is the most common cause and is often not rechallenged. Alternative non-hepatotoxic drugs (Ethambutol, a fluoroquinolone) may bridge the gap.

Reference: NICE NG33 2016 – TB; BTS 2024 – Drug-induced liver injury in TB