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Colchicine toxicity — GPhC CRA MCQ

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HardMusculoskeletal TherapeuticsColchicine toxicityGPhC CRA

A 77-year-old man with gout is prescribed colchicine 500 micrograms twice daily. He has eGFR 24mL/min/1.73m2 and is taking clarithromycin for pneumonia. What is the most important interaction to flag?

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Correct answer: C — Query urgently because colchicine toxicity risk is high with renal impairment and clarithromycin

Colchicine toxicity can be serious and is more likely in renal impairment. Clarithromycin can markedly increase colchicine exposure through CYP3A4/P-gp inhibition. The combination in a patient with eGFR 24mL/min/1.73m2 requires urgent prescriber review. Diarrhoea can be an early sign of toxicity and should not simply be masked.

Reference: BNF