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Theophylline and ciprofloxacin — GPhC CRA MCQ

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HardRespiratory TherapeuticsTheophylline and ciprofloxacinGPhC CRA

A patient taking theophylline modified-release 300 mg twice daily is prescribed ciprofloxacin for a urinary infection. They report previous theophylline toxicity. 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 — Raised theophylline concentrations with toxicity risk

Ciprofloxacin can increase theophylline exposure and toxicity risk, requiring prescriber review. The best answer addresses the key safety, legal or pharmaceutical care issue in the vignette. The other options would either delay appropriate care, create a new risk, or fail to resolve the issue. This is consistent with the cited UK reference for safe pharmacy practice.

Reference: BNF; NICE CKS; BTS/NICE/SIGN asthma guideline