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Theophylline and ciprofloxacin — GPhC CRA MCQ

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ModerateRespiratory TherapeuticsTheophylline and ciprofloxacinGPhC CRA

A 58-year-old man takes theophylline modified-release 300mg twice daily for COPD. He is prescribed ciprofloxacin for a urinary tract infection. He reports nausea and tremor after the first day. What is the most important interaction to flag?

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Correct answer: A — Ciprofloxacin can increase theophylline levels and toxicity risk

Ciprofloxacin can inhibit theophylline metabolism and increase the risk of toxicity. Symptoms such as nausea and tremor are concerning early features. The prescriber should be contacted to consider an alternative antibiotic or close monitoring of theophylline levels and symptoms.

Reference: BNF