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Carbamazepine and contraception — GPhC CRA MCQ

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ModerateCNS TherapeuticsCarbamazepine and contraceptionGPhC CRA

A 24-year-old woman taking carbamazepine for epilepsy asks for the combined oral contraceptive pill. She has no contraindication to oestrogen and wants reliable contraception. What is the most important interaction to flag?

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

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Correct answer: C — Carbamazepine can reduce hormonal contraceptive effectiveness by enzyme induction

Carbamazepine is a hepatic enzyme inducer and can reduce the effectiveness of many hormonal contraceptives. The patient should be advised about more reliable options such as an intrauterine method or depot injection depending on guidance and suitability. Specialist or contraception service referral is appropriate.

Reference: BNF; FSRH guidance