Trial reportBritish journal of pharmacology2008
Pharmacodynamic interaction of warfarin with cranberry but not with garlic in healthy subjects.
Trial report in British journal of pharmacology, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 40 papers, 5 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
40 citing papers in PubMed, 5 syntheses or guidelines pooled it, 137 citations in OpenAlex.
- Cranberry-derived bioactives for the prevention and treatment of urinary tract infections: antimicrobial mechanisms and global research trends in nutraceutical applications.Frontiers in nutrition · 2025Pooled it
- Naturopathic Treatment and Complementary Medicine in Surgical Practice.Deutsches Arzteblatt international · 2018Pooled it
- A systematic review of the pharmacokinetic and pharmacodynamic interactions of herbal medicine with warfarin.PloS one · 2017Pooled it
- Interactions of commonly used dietary supplements with cardiovascular drugs: a systematic review.Systematic reviews · 2012Pooled it
- Interactions between herbal medicines and prescribed drugs: an updated systematic review.Drugs · 2009Pooled it
- Absence of pharmacokinetic and pharmacodynamic interactions between almorexant and warfarin in healthy subjects.Drugs in R&D · 2013Trial
- Effect of single-dose rifampin on the pharmacokinetics of warfarin in healthy volunteers.Clinical pharmacology and therapeutics · 2010Trial
- Herbal Medicines and Drugs Interactions: Cytochrome P450 Responsibility.Current medicinal chemistry · 2026Review
- A Narrative Review on Plant Extracts for Metabolic Syndrome: Efficacy, Safety, and Technological Advances.Nutrients · 2025Review
- Adjuvant Anti-tumor Therapy with Polyphenolic Compounds: A Review.Current medicinal chemistry · 2025Review
- Effect of Daridorexant on the Pharmacokinetics of Midazolam, and on the Pharmacokinetics and Pharmacodynamics of Warfarin in Healthy Male Subjects.Drugs in R&D · 2024Article
- Safety Issues of Herb-Warfarin Interactions.Current drug metabolism · 2024Review
- Possible Side Effects of Polyphenols and Their Interactions with Medicines.Molecules (Basel, Switzerland) · 2023Review
- Review
- Herb-Drug Interaction in Inflammatory Diseases: Review of Phytomedicine and Herbal Supplements.Journal of clinical medicine · 2022Review
- The influence of Javanese turmeric (Pharmaceutical biology · 2021Article
- Herb-Drug Interactions: Worlds Intersect with the Patient at the Center.Medicines (Basel, Switzerland) · 2021Review
- Pharmacokinetic Interactions between Cardiovascular Medicines and Plant Products.Cardiovascular therapeutics · 2019Review
- Therapeutic Risk and Benefits of Concomitantly Using Herbal Medicines and Conventional Medicines: From the Perspectives of Evidence Based on Randomized Controlled Trials and Clinical Risk Management.Evidence-based complementary and alternative medicine : eCAM · 2017Review
- Pharmacogenomics and herb-drug interactions: merge of future and tradition.Evidence-based complementary and alternative medicine : eCAM · 2015Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 4 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
background and purposePatients commonly take complementary medicines in conjunction with warfarin yet evidence supporting the safety or the risk of a herb-drug interaction is lacking. The aim of this study was to investigate the possible impact of two commonly used herbal medicines, garlic and cranberry, on the pharmacokinetics and pharmacodynamics of warfarin in healthy male subjects. EXPERIMENTAL APPROACH: An open-label, three-treatment, randomized crossover clinical trial was undertaken and involved 12 healthy male subjects of known CYP2C9 and VKORC1 genotype. A single dose of 25 mg warfarin was administered alone or after 2 weeks of pretreatment with either garlic or cranberry. Warfarin enantiomer concentrations, INR, platelet aggregation and clotting factor activity were measured to assess pharmacokinetic and pharmacodynamic interactions between warfarin and herbal medicines. KEY
resultsCranberry significantly increased the area under the INR-time curve by 30% when administered with warfarin compared with treatment with warfarin alone. Cranberry did not alter S- or R-warfarin pharmacokinetics or plasma protein binding. Co-administration of garlic did not significantly alter warfarin pharmacokinetics or pharmacodynamics. Both herbal medicines showed some evidence of VKORC1 (not CYP2C9) genotype-dependent interactions with warfarin, which is worthy of further investigation. CONCLUSIONS AND IMPLICATIONS: Cranberry alters the pharmacodynamics of warfarin with the potential to increase its effects significantly. Co-administration of warfarin and cranberry requires careful monitoring.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.