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Colchicine clarithromycin renal — GPhC CRA MCQ

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HardMusculoskeletal TherapeuticsColchicine clarithromycin renalGPhC CRA

An older adult with chronic kidney disease takes colchicine for an acute gout flare and is prescribed clarithromycin. They now report diarrhoea and muscle weakness. What should the pharmacist do?

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Correct answer: DStop colchicine and obtain urgent toxicity and interaction assessment

Stop colchicine and obtain urgent toxicity and interaction assessment: Clarithromycin strongly inhibits colchicine elimination; renal impairment greatly increases potentially fatal gastrointestinal, neuromuscular and marrow toxicity. Continue both medicines with doses separated by at least twelve hours: Persistent CYP3A4 and transporter inhibition is not prevented by temporal separation. Continue both medicines and add loperamide for current gastrointestinal symptoms: Diarrhoea may herald colchicine toxicity and masking it while exposure continues is unsafe. Increase colchicine during clarithromycin treatment to maintain flare control: Clarithromycin increases colchicine exposure and dose escalation can be fatal. Continue colchicine and stop clarithromycin when the gout flare resolves: The hazardous exposure is occurring now and symptoms require immediate action.

Reference: BNF: colchicine: https://bnf.nice.org.uk/drugs/colchicine/; BNF: clarithromycin: https://bnf.nice.org.uk/drugs/clarithromycin/