Aspirin and dipyridamole and Warfarin interaction
Aspirin and dipyridamole and Warfarin: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Aspirin and dipyridamole label · effective 2023-12-26
Aspirin can displace warfarin from protein binding sites, leading to prolongation of both the prothrombin time and the bleeding time.
Risk factors for bleeding include the use of other drugs that increase the risk of bleeding (e.g., anticoagulants, antiplatelet agents, heparin, anagrelide, fibrinolytic therapy, and chronic use of NSAIDs) [see Drug Interactions ( 7.1 )].
• Co-administration with anticoagulants, antiplatelets, or NSAIDs can increase risk of bleeding ( 7.1 )
Anticoagulants and Antiplatelets Patients taking aspirin and extended-release dipyridamole capsules in combination with anticoagulants, antiplatelets, or any substance impacting coagulation are at increased risk for bleeding.
Aspirin can increase the anticoagulant activity of heparin, increasing bleeding risk.
From the Warfarin (Warfarin Sodium) label · effective 2026-06-24
…Drugs Anticoagulants argatroban, dabigatran, bivalirudin, desirudin, heparin, lepirudin Antiplatelet Agents aspirin, cilostazol, clopidogrel, dipyridamole, prasugrel, ticlopidine Non-steroidal Anti-Inflammatory Agents celecoxib, diclofenac, diflunisal, fenoprofen, ibuprofen, indomethacin, ketoprofen, ketorolac, mefenamic acid, naproxen, oxaprozin, piroxicam,…
Some botanicals may cause bleeding events when taken alone (e.g., garlic and Ginkgo biloba) and may have anticoagulant, antiplatelet, and/or fibrinolytic properties.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.