warfarin and combined oral contraceptive pill
Last reviewed 01/2018
- coumarin anticoagulants (e.g. warfarin)
- use of estrogens and/or progestogens has been associated with both increased and decreased anticoagulant effect of coumarin anticoagulants. Given the lack of consistent evidence a true interaction is unlikely
Reference:
- Faculty of Sexual & Reproductive Healthcare Clinical Guidance. Drug Interactions with Hormonal Contraception.Clinical Effectiveness Unit; January 2011.