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Smoking and theophylline — GPhC CRA MCQ

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HardRespiratory TherapeuticsSmoking and theophyllineGPhC CRA

A patient stable on theophylline starts carbamazepine for focal seizures. What interaction should be anticipated?

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Correct answer: C — Enzyme induction may lower theophylline concentration

Carbamazepine induces hepatic enzymes and can increase theophylline clearance, reducing exposure and asthma or COPD control. Concentrations, symptoms and dose may need review both when the inducer is started and when it is later stopped.

Reference: https://www.pharmacyregulation.org/students-and-trainees/pharmacist-education-and-training/registration-assessment