Abstract
Based on anecdotal reports, the question of whether cranberry juice interacts with
warfarin has been raised. This article discusses the potential mechanism, and systematically
reviews case reports as well as clinical trials examining the possible interaction.
We systematically searched MEDLINE via PubMed, and the Cochrane Library database.
Fifteen case reports were summarized, including the initial unpublished brief reports
to the Committee on Safety of Medicines and the subsequent 6 published case reports.
Seven clinical trials were analyzed, including 3 studies using warfarin and 4 surrogate
drugs. Only 2 cases had a validation scale suggesting a “probable” interaction, but
even in these patients there were many reasons to question the validity of a relevant
drug interaction. Randomized clinical trials and surrogate markers found no evidence
to support the interaction between cranberry juice and warfarin. Because the moderate
consumption of cranberry juice does not affect anticoagulation, we encourage the reexamination
of initial warnings based on scientific evidence. We conclude that the initial precautionary
warnings by administrating bodies are limited to anecdotal case reports and represent
misleading conclusions.
Keywords
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Article Info
Footnotes
Funding: There was no sponsor for this study.
Conflict of Interest: Jennifer Zikria, none; Raimonda Goldman, none; a prior study by Jack Ansell was supported in part by a grant from the Ocean Spray Co. , and he has been a consultant for the Cranberry Institute of America.
Authorship: Jennifer Zikria performed a literature search, created tables, performed data interpretation for case reports and clinical trials, and wrote the manuscript. Raimonda Goldman performed data interpretation for case reports and reviewed the manuscript. Jack Ansell reviewed, modified, and edited the manuscript.
Identification
Copyright
© 2010 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
