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Clarithromycin and calcium-channel blockers — GPhC CRA MCQ

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HardDrug InteractionsClarithromycin and calcium-channel blockersGPhC CRA

A 76-year-old woman taking felodipine modified-release is prescribed clarithromycin. She has had recent dizzy spells and low blood pressure. What is the most important interaction to flag?

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Correct answer: C — Clarithromycin can increase felodipine exposure and worsen hypotension

Clarithromycin inhibits CYP3A4 and can increase levels of calcium-channel blockers such as felodipine. This may cause hypotension, dizziness or acute kidney injury in susceptible patients. Prescriber review is appropriate.

Reference: BNF