skip to main content

Ciprofloxacin and theophylline — GPhC CRA MCQ

Instant feedback + full explanation. One question, done properly.

HardRespiratory TherapeuticsCiprofloxacin and theophyllineGPhC CRA

A 44-year-old man taking theophylline modified-release 300mg twice daily is prescribed ciprofloxacin 500mg twice daily for suspected epididymo-orchitis. He reports palpitations when his theophylline level is high. The prescriber has not mentioned monitoring. What is the most important interaction to flag?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

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

Ciprofloxacin can inhibit theophylline metabolism and increase toxicity risk. Palpitations are a relevant previous toxicity symptom. The pharmacist should contact the prescriber to consider an alternative antibiotic or monitoring and dose adjustment.

Reference: BNF