Selected Anticoagulants (Vitamin K antagonists)/Aspirin (Greater Than 100 Interactions
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Medical warning:
Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, aspirin or similar medicine may decrease the ability of your blood to clot properly and/or may cause stomach irritation.
What might happen:
You may experience an increased chance for bleeding. Symptoms may include: bleeding from your gums, nosebleeds, unusual bruising, red or orange urine, severe headache, coughing up blood, blood in vomit, or dark/black/tarry stools.
What you should do about this interaction:
Ask your healthcare professionals (e.g. doctor or pharmacist) about taking these medicines together. They may recommend a non-aspirin product. If your doctor prescribes these medicines together, you may need to have laboratory testing more often.If you have any signs of bleeding such as bleeding from your gums, nosebleeds, unusual bruising, red or orange urine, severe headache, coughing up blood, blood in vomit, or dark/black/tarry stools contact your doctor right away.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
- 1.Quick AJ, Clesceri L. Influence of acetylsalicylic acid and salicylamide on the coagulation of blood. J Pharmacol Exp Ther 1960;128:95-8.
- 2.Watson RM, Pierson RN Jr. Effect of anticoagulant therapy upon aspirin-induced gastrointestinal bleeding. Circulation 1961 Sep;24:613-6.
- 3.Barrow MV, Quick DT, Cunningham RW. Salicylate hypoprothrombinemia in rheumatoid arthritis with liver disease. Report of two cases. Arch Intern Med 1967 Nov;120(5):620-4.
- 4.Weiss HJ, Aledort LM, Kochwa S. The effect of salicylates on the hemostatic properties of platelets in man. J Clin Invest 1968 Sep; 47(9):2169-80.
- 5.Udall JA. Drug interference with warfarin therapy. Clin Med 1970 Aug; 77:20-5.
- 6.Fausa O. Salicylate-induced hypoprothrombinemia. A report of four cases. Acta Med Scand 1970 Nov;188(5):403-8.
- 7.Zucker MB, Peterson J. Effect of acetylsalicylic acid, other nonsteroidal anti-inflammatory agents, and dipyridamole on human blood platelets. J Lab Clin Med 1970 Jul;76(1):66-75.
- 8.O'Reilly RA, Sahud MA, Aggeler PM. Impact of aspirin and chlorthalidone on the pharmacodynamics of oral anticoagulant drugs in man. Ann N Y Acad Sci 1971 Jul 6;179:173-86.
- 9.Dale J, Myhre E, Loew D. Bleeding during acetylsalicylic acid and anticoagulant therapy in patients with reduced platelet reactivity after aortic valve replacement. Am Heart J 1980 Jun;99(6):746-52.
- 10.Donaldson DR, Sreeharan N, Crow MJ, Rajah SM. Assessment of the interaction of warfarin with aspirin and dipyridamole. Thromb Haemost 1982 Feb 26;47(1):77.
- 11.Chesebro JH, Fuster V, Elveback LR, McGoon DC, Pluth JR, Puga FJ, Wallace RB, Danielson GK, Orszulak TA, Piehler JM, Schaff HV. Trial of combined warfarin plus dipyridamole or aspirin therapy in prosthetic heart valve replacement: danger of aspirin compared with dipyridamole. Am J Cardiol 1983 May 15;51(9):1537-41.
- 12.Chow WH, Cheung KL, Ling HM, See T. Potentiation of warfarin anticoagulation by topical methylsalicylate ointment. J R Soc Med 1989 Aug;82(8):501-2.
- 13.Meade TW, Roderick PJ, Brennan PJ, Wilkes HC, Kelleher CC. Extra-cranial bleeding and other symptoms due to low dose aspirin and low intensity oral anticoagulation. Thromb Haemost 1992 Jul 6;68(1):1-6.
- 14.Dentali F, Douketis JD, Lim W, Crowther M. Combined aspirin-oral anticoagulant therapy compared with oral anticoagulant therapy alone among patients at risk for cardiovascular disease: a meta-analysis of randomized trials. Arch Intern Med 2007 Jan 22;167(2):117-24.
- 15.Grosser T Smyth E FitzGerald GA. Anti-Inflammatory, Antipyretic and Analgesic Agents; Pharmacotherapy of Gout. In Bruton L, Chabner B, Knollman B eds. Goodman & Gilman's The Pharmacological Basis of Therapeutics. 12th ed. 2011.
- 16.Zhou M, Leonard CE, Brensinger CM, Bilker WB, Kimmel SE, Hecht TEH, Hennessy S. Pharmacoepidemiologic Screening of Potential Oral Anticoagulant Drug Interactions Leading to Thromboembolic Events. Clin Pharmacol Ther 2020 Aug;108(2):377-386.
- 17.Wang M, Zeraatkar D, Obeda M, Lee M, Garcia C, Nguyen L, Agarwal A, Al-Shalabi F, Benipal H, Ahmad A, Abbas M, Vidug K, Holbrook A. Drug-drug interactions with warfarin: A systematic review and meta-analysis. Br J Clin Pharmacol 2021 Nov;87(11):4051-4100.
Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, except as may be authorized by the applicable terms of use.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.