In general, appropriately managed anticoagulation (usually this means Coumadin [generic – warfarin]) may prolong clotting for a short period. The usual treatment methods should be sufficient, i.e. direct pressure, to control bleeding. If a major vascular structure, either vein or artery, is involved it’s a different story and Quikclot or similar products may have some utility. Just asking – Has your friend had a blood test recently to asses his anticoagulant’s effect determined? Unfortunately this sometimes isn’t followed as closely as it should be. Many things affect warfarin’s effect, most of them potentiate the effects and excessive prolongation of bleeding times results. Here’s a link re: warfarin: http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682277.html

Good luck. Hope this helps some.
I agree with Susan's advice.