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Macrolide statin interaction — GPhC CRA MCQ

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EasyInfectionsMacrolide statin interactionGPhC CRA

A 64-year-old man taking simvastatin 40 mg nightly is prescribed clarithromycin 500 mg twice daily for pneumonia. He has no known liver disease and his renal function is normal. What is the most important interaction to flag?

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Correct answer: B — Clarithromycin can increase simvastatin concentration and myopathy risk

Clarithromycin strongly inhibits CYP3A4 and can markedly increase exposure to simvastatin. This raises the risk of myopathy and rhabdomyolysis. The prescriber should consider holding simvastatin during treatment or choosing an alternative antibiotic where suitable.

Reference: BNF