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Loperamide use — GPhC CRA MCQ

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HardGastrointestinal TherapeuticsLoperamide useGPhC CRA

An 82-year-old takes colchicine 500 micrograms once daily for gout prophylaxis and has an eGFR of 38 mL/min/1.73 m². A new prescription for clarithromycin 500 mg twice daily is presented. What is the most appropriate supply action?

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Correct answer: E — Withhold supply and contact the prescriber for a non-interacting treatment plan

Colchicine is a CYP3A4 and P-glycoprotein substrate. Clarithromycin can markedly increase colchicine exposure, and toxicity including deaths has been reported, especially in older people with renal impairment. The authorised information contraindicates colchicine in renal or hepatic impairment when a strong CYP3A4 inhibitor such as clarithromycin is used. Dose reduction or dose separation does not make this patient’s combination acceptable; supply should be withheld while the prescriber selects a non-interacting plan.

Reference: Colchicine 500 microgram tablets SmPC: https://www.medicines.org.uk/emc/product/100968/smpc