Green Tea - Activase (Alteplase, tPA) Interaction
Herbal: Green Tea
Also Known As: Camellia sinensis, Green Sencha Tea, Green Tea Extract, GTP, GTPF, Japanese Sencha Green Tea, Japanese Tea, Kunecatechins, Poly E, Polyphenon E, PTV, Té Verde, Tea Extract, Tea Green, Tea, Thé, Thé Vert, Yabukita, Yame Green Tea, Yame Tea
Drug: Alteplase, tPA
Brand names:
Activase, Actilyse
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jul 22, 2023
Interaction Details
Alteplase, tPA is classified as belonging to the following category: Anticoagulant/Antiplatelet Drugs
Theoretically, green tea may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Conflicting reports exist regarding the effect of green tea on bleeding risk when used with anticoagulant or antiplatelet drugs; however, most evidence suggests that drinking green tea in moderate amounts is unlikely to cause a significant interaction. Green tea contains small amounts of vitamin K, approximately 7 mcg per cup. Some case reports have associated the antagonism of warfarin with the vitamin K content of green tea. However, these reports are rare, and very large doses of green tea (about 8-16 cups daily) appear to be needed to cause these effects. Furthermore, the catechins and caffeine in green tea are reported to have antiplatelet activity.
Interaction Rating
Likelihood of Occurrence
UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
References
- Mitscher LA, Mitscher LA, Jung M, Shankel D, et al. Chemoprotection: a review of the potential therapeutic antioxidant properties of green tea (Camellia sinensis) and certain of its constituents. Med Res Rev 1997;17:327-65.
- Booth SL, Madabushi HT, Davidson KW, et al. Tea and coffee brews are not dietary sources of vitamin K-1 (phylloquinone). J Am Diet Assoc 1995;95:82-3.
- Lou FQ, Zhang MF, Zhang XG, et al. A study on tea-pigment in prevention of atherosclerosis. Chin Med J (Engl) 1989;102:579-83.
- Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-50.
- Taylor JR, Wilt VM. Probable antagonism of warfarin by green tea. Ann Pharmacother 1999;33:426-8.
- Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm 2000;57:1221-7.
- Ali M, Afzal M. A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea. Prostaglandins Leukot Med 1987;27:9-13.
- Ardlie NG, Glew G, Schultz BG, Schwartz CJ. Inhibition and reversal of platelet aggregation by methyl xanthines. Thromb Diath Haemorrh 1967;18:670-3.
- Son DJ, Cho MR, Jin YR, et al. Antiplatelet effect of green tea catechins: a possible mechanism through arachidonic acid pathway. Prostaglandins Leukot Essent Fatty Acids 2004;71:25-31.
- Chan, H. T., So, L. T., Li, S. W., Siu, C. W., Lau, C. P., and Tse, H. F. Effect of herbal consumption on time in therapeutic range of warfarin therapy in patients with atrial fibrillation. J.Cardiovasc.Pharmacol. 2011;58(1):87-90.
- Nutescu EA, Shapiro NL, Ibrahim S, et al. Warfarin and its interactions with foods, herbs and other dietary supplements. Expert Opin Drug Saf. 2006;5(3):433-51.
Green Tea Overview
Green tea is a type of tea that is made from the leaves of the Camellia sinensis plant. It is native to Asia and is widely consumed throughout the world. Green tea has a mild, slightly grassy flavor and is typically lighter in color and less astringent than black tea.
Green tea is a rich source of antioxidants, particularly a group of compounds called catechins. These antioxidants are thought to help protect cells from damage caused by free radicals. Green tea is also a good source of other nutrients, including vitamin C and several B vitamins.
Green tea is often consumed for a number of purported health benefits including reducing the risk of heart disease, immune-stimulating effects, and weight loss.
Oral green tea supplements, containing dried powder, are most often utilized for the caffeine content and used as an appetite suppressant for weight loss.
Green Tea - More Interactions
Green Tea interacts with 1188 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Drug descriptions are provided by MedlinePlus.
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In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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