Because of the possible antithrombotic effect of fish oil supplements, hemophiliacs and those taking warfarin (Coumadin), or other anticoagulants or antiplatelet drugs such as aspirin, clopidogrel (Plavix), dalteparin (Fragmin), dipyridamole (Persantine), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid) and others should exercise caution in use of fish oils.