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Theophylline interaction — GPhC CRA MCQ

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HardRespiratory TherapeuticsTheophylline interactionGPhC CRA

A patient taking theophylline modified-release tablets for COPD is prescribed ciprofloxacin for a suspected urinary tract infection. The pharmacy system flags an interaction. What is the most important interaction to flag?

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

Ciprofloxacin can inhibit theophylline metabolism and increase the risk of toxicity, including nausea, tremor, seizures, and arrhythmia. The prescriber should be contacted to consider an alternative antibiotic or monitoring plan. The other effects are not the principal interaction.

Reference: BNF