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Macrolide and calcium-channel blocker — GPhC CRA MCQ

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ModerateDrug InteractionsMacrolide and calcium-channel blockerGPhC CRA

An older patient taking felodipine is prescribed clarithromycin for sinusitis. His daughter reports previous dizziness with low blood pressure. What is the most important interaction to flag?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: A — Clarithromycin can increase felodipine levels and hypotension risk

Clarithromycin inhibits CYP3A4 and can increase concentrations of some calcium-channel blockers. Older age and prior hypotension increase the risk of dizziness, falls and harm. The other options either delay appropriate care, use an unsuitable medicine, or miss the main safety issue.

Reference: BNF