Tier 4 — mechanistic

Enhanced Anticoagulant Effect of Warfarin When Co-administered With Quercetin

Ruchit Patel, Allison Stine, Kimberly Zitko
The Journal of pharmacy technology : jPT : official publication of the Association of Pharmacy Technicians 2022 38(6):374-375

Bibliography

PubMed
PMID 36311308
PubMed Central
PMC9608098
DOI
10.1177/87551225221125667
Funding
Funding was not specified in the indexed record or the disclosure metadata available for this entry.
Competing interests
Reported disclosure: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study snapshot

DesignPublished clinical drug-interaction case report
ModelHuman case report
Sample1 man aged 79 years
InterventionQuercetin 250 mg plus vitamin C 500 mg/day added to stable warfarin therapy
DurationSeveral days before an INR increase; follow-up after discontinuation
EndpointsPlatelet or coagulation measurements

What the study showed, in plain terms

Published in 2022, this source examined safety, interactions and special populations. Design: Published clinical drug-interaction case report. Sample/model: 1 man aged 79 years. The exposure or intervention was Quercetin 250 mg plus vitamin C 500 mg/day added to stable warfarin therapy. Follow-up or treatment period: Several days before an INR increase; follow-up after discontinuation.

INR rose to 7.5 after supplement initiation and returned toward the therapeutic range after withdrawal; no bleeding was reported.

Single case with concurrent medicines and a combined supplement. A possible interaction signal does not prove causality or quantify its frequency.

Continue with Quercetin Data Center

For topic-level interpretation, read Quercetin Interactions: Medicines, Evidence and Precautions. This is a related guide; the citation panel separately identifies articles that directly cite this paper.

Key findings

  • INR rose to 7.5 after supplement initiation and returned toward the therapeutic range after withdrawal; no bleeding was reported.
  • The recorded outcome domains were Platelet or coagulation measurements.

What this study can and cannot tell us

  • Single case with concurrent medicines and a combined supplement. A possible interaction signal does not prove causality or quantify its frequency.
  • A case report or series cannot estimate how often an event occurs or establish causality without alternative explanations and a suitable comparator.
  • Source basis: Source check: published case description and PubMed bibliographic metadata. Missing method details, funding information or participant denominators are not inferred.

Citation network

Articles citing this research paper

2 articles

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Editorial review

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Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction Dr. Amr Yasser, PhDCardiometabolic, Musculoskeletal, Gut & Bioavailability Dr. Abdulla Mostafa, PhDCellular Senescence, Neurological, Mitochondrial & Brain-Ageing Biology