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Theophylline interaction risk — GPhC CRA MCQ

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HardRespiratory TherapeuticsTheophylline interaction riskGPhC CRA

A patient stabilised on theophylline for COPD is prescribed ciprofloxacin for a suspected infection. The GP asks the pharmacist to check the prescription. What is the most important interaction to flag?

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

Ciprofloxacin can inhibit theophylline metabolism, increasing the risk of nausea, tachycardia, arrhythmia and seizures. The combination should generally be avoided or carefully monitored if necessary. An alternative antibiotic may be more appropriate depending on infection and sensitivities. This is a high-risk interaction because theophylline has a narrow therapeutic index.

Reference: BNF