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Liver enzyme inducer EC — DFSRH MCQ

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HardEmergency contraceptionLiver enzyme inducer ECDFSRH

A patient taking phenytoin presents 36 hours after unprotected sexual intercourse. She declines a Cu-IUD today. Which oral emergency-contraception regimen is most appropriate?

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Correct answer: B — Levonorgestrel 3 mg orally as a single dose

A Cu-IUD is the preferred emergency contraception option during use of an enzyme-inducing medicine because its effectiveness is not affected. If it is declined, CoSRH/FSRH advises levonorgestrel 3 mg as the oral option. Ulipristal acetate is not recommended with enzyme induction, and standard-dose levonorgestrel may be less effective.

Reference: CoSRH/FSRH, Emergency contraception guideline (amended July 2023): https://www.cosrh.org/Common/Uploaded%20files/documents/fsrh-guideline-emergency-contraception03dec2020-amendedjuly2023-11jul.pdf