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Theophylline and ciprofloxacin — GPhC CRA MCQ

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EasyDrug InteractionsTheophylline and ciprofloxacinGPhC CRA

A patient taking theophylline modified-release for COPD is prescribed ciprofloxacin for suspected infection. He reports feeling shaky when medicines are changed. What is the most important interaction to flag?

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Correct answer: E — Ciprofloxacin can increase theophylline concentration and toxicity

Ciprofloxacin can inhibit theophylline metabolism and increase theophylline concentrations, risking nausea, tremor, arrhythmias and seizures. The combination should be avoided where possible or closely monitored if essential. The patient's symptoms could be compatible with stimulant adverse effects and warrant caution. The issue is increased theophylline exposure, not reduced absorption.

Reference: BNF