Health professionals warn of bleeding risk when taking herbs, supplements

In moderation, most food, herbs, and supplements can be safely taken, but patients on warfarin must be mindful of the increased risk of bleeding when taking these things, suggest the results of a recent study.

In particular, they should be aware of the effects of the following: Chinese wolfberry, chamomile tea, cannabis, cranberry, chitosan, green tea, Ginkgo biloba, ginger, spinach, St. John’s Wort, sushi, and tobacco smoking.

The investigators presented an updated overview on the safety of concurrent use of food, herbal, or dietary supplement and warfarin. They performed a systematic review on five databases from inception up to 31 December 2019 and classified such use depending on the likelihood of interaction and supporting evidences.

A total of 149 articles were identified, reporting 78 herbs, food, or dietary supplements that had interactions with warfarin. The studies described potentiation with 45 (57.7 percent) herbs, food, or dietary supplements, inhibition with 23 (29.5 percent), and limited impact with 10 (12.8 percent) on warfarin pharmacokinetics and pharmacodynamics.

In addition, 20 unique herbs and dietary supplements were found to be associated with minor bleeding events, including purpura and gum bleeding, as well as major events such as intracranial bleeding that could lead to death.

“Patients should be counselled to continue to seek advice from their healthcare professionals when starting any new herbs, food, or supplement,” the investigators said.