St John’s wort causes most drug interactions, finds reviewBMJ 2012; 345 doi: http://dx.doi.org/10.1136/bmj.e7295 (Published 29 October 2012) Cite this as: BMJ 2012;345:e7295
- Lilian Anekwe
- 1BMJ Evidence Centre
Warfarin, insulin, aspirin, digoxin, and ticlopidine had the greatest number of reported interactions with herbal and dietary supplements, a systematic review of 85 studies has found.
Most problems were caused by ingredients such as St John’s wort, magnesium, calcium, iron, and ginkgo, says the review in the International Journal of Clinical Practice.1 Each of these has been documented to interact with 147, 102, 75, 71, and 51 individual drugs respectively.