Drug points: Apparent interaction between warfarin and levonorgestrel used for emergency contraception

Abstract
Emergency contraception with progestogen only (two doses of levonorgestrel 0.75 mg given 12 hours apart and within 72 hours of unprotected intercourse) is better tolerated and more effective than the combined oestrogen-progestogen (Yuzpe) regimen.1 Furthermore, treatment with progestogen only may be preferable to the Yuzpe regimen in women with a known thrombophilic defect or history of thromboembolic events. For women receiving warfarin, drug information cites either no interaction between progestogens and warfarin2 or a …