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TB Drug Hepatotoxicity — SCE Infectious Diseases MCQ

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ModerateTuberculosisTB Drug HepatotoxicitySCE Infectious Diseases

A 42-year-old healthcare worker with known latent TB is started on Isoniazid 300 mg daily plus Rifampicin for 3 months. At week 6, her ALT rises to 180 U/L (4.5× ULN). She is asymptomatic. What is the appropriate action?

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Correct answer: D — Continue treatment but increase monitoring frequency to twice-weekly LFTs; stop if ALT >5× ULN or symptoms develop

During latent TB treatment, mild ALT elevation (up to 5× ULN without symptoms) can be managed with increased monitoring frequency. Treatment should be stopped if ALT exceeds 5× ULN in asymptomatic patients, or >3× ULN with symptoms (nausea, vomiting, abdominal pain, jaundice). At 4.5× ULN without symptoms, closer monitoring (twice-weekly LFTs) is appropriate while continuing treatment. This patient is close to the threshold, so careful observation is critical.

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