Food and medicine interaction
Chamomile tea and chamomile products and warfarin
ProbableEvidence level: probable. Case reports in people plus a known mechanism, but no controlled studies.
Last reviewed
What can happen
A published case described a 70-year-old woman on warfarin admitted with multiple internal bleeds after using chamomile tea and lotion. NCCIH notes reported interactions between chamomile and warfarin and some drugs metabolized by the liver.
- Why it happens
- Chamomile contains coumarin compounds and may affect drug-metabolizing enzymes; the exact mechanism is unproven.
- At ordinary food amounts
- The case involved repeated tea plus lotion. Occasional cups are less likely to matter, but evidence is limited to case reports.
What to do
If you take warfarin, tell your anticoagulation clinic before drinking chamomile tea regularly. NCCIH also suggests caution combining chamomile with sedatives.
Never stop or change a prescribed medicine without talking to the prescriber.
Common questions
Can I have chamomile tea and chamomile products while taking anticoagulants?
If you take warfarin, tell your anticoagulation clinic before drinking chamomile tea regularly. NCCIH also suggests caution combining chamomile with sedatives. The case involved repeated tea plus lotion. Occasional cups are less likely to matter, but evidence is limited to case reports.
Sources
- Segal R, Pilote L. Warfarin interaction with Matricaria chamomilla. CMAJ. 2006. PMID 16636327.
- National Center for Complementary and Integrative Health. Chamomile: Usefulness and Safety.
- Tan CSS, Lee SWH. Warfarin and food, herbal or dietary supplement interactions: a systematic review. Br J Clin Pharmacol. 2021. PMID 32478963.
Related
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