Topiramate contraceptive interaction — DFSRH MCQ

Correct answer: C — Discuss reduced hormonal contraceptive efficacy and offer an unaffected method such as Cu-IUD or LNG-IUD

The best answer is “Discuss reduced hormonal contraceptive efficacy and offer an unaffected method such as Cu-IUD or LNG-IUD”. Topiramate at higher doses can reduce hormonal contraceptive effectiveness, so an unaffected method such as intrauterine contraception should be discussed. Continuing CHC without counselling misses a clinically important interaction. Planned monthly EC or repeated UPA is not a substitute for reliable contraception, and simply increasing oestrogen is not the preferred solution. The pearl is that migraine therapy can affect contraceptive choice even when migraine itself lacks aura. Combined hormonal contraception must be assessed by applying oestrogen-related arterial and venous risk, the exact timing of incorrect use, drug interactions and the need for emergency contraception. A non-oestrogen method may be acceptable even when CHC is not. Missed-use advice depends on whether the hormone-free interval was extended, rather than simply on the number of tablets mentioned.

Reference: CoSRH/FSRH, Combined Hormonal Contraception (January 2019, amended October 2023): https://www.cosrh.org/Common/Uploaded%20files/documents/fsrh-guideline-combined-hormonal-contraception-october-2023.pdf