St John's Wort and warfarin
Last reviewed 01/2018
The interaction of warfarin and St John's wort (SJW) leads to a reduction in the anticoagulant effect of warfarin.
Suggested management of patients taking SJW and warfarin:
- stop SJW and check INR
- the INR should be monitored closely because this may rise on stopping SJW
- it may be necessary to adjust the warfarin dose