cranberry
2 interactions related to cranberry
cranberry + warfarin
Cranberry contains flavonoids and polyphenols that may slow CYP2C9, the liver enzyme that clears the more potent S-enantiomer of warfarin. Multiple human case reports describe a rising INR and serious bleeding in patients who took up cranberry juice or supplements while stably anticoagulated, and the effect appears to depend on how much cranberry is consumed: randomized trials using a modest daily amount have not consistently reproduced it.
cranberry + tacrolimus
The only human report on cranberry and tacrolimus showed tacrolimus levels falling sharply, not rising; lab studies predict the opposite, so the true direction is genuinely unpredictable. Because tacrolimus has a very narrow therapeutic window, any change in cranberry intake deserves a trough check.