Greetings Welcome to Healthcaremagic. Purple patches while taking warfarin is a common problem with this medication . Warfarin is suppose to avoid clotting in those patient that have blocked blood vessels anywhere in the body. For this problem warfarin is taken for a long time . But when taken in larger than required dose or when another medication is also taken with warfarin , its clotting inhibition effect is enhanced and we can have bleeding from different site. The purple patches that are noted are actually bleeding in the skin. While taking warfarin two points needs to be taken care of . First is that no other medication that interacts with warfarin should be taken unless advised by doctor after careful dose adjustment of warfarin . Secondly , a blood test by the name of INR should be done once in awhile , especially when one develops bleeding or purple patches. INR shows how reduced is the clotting ability of the blood . this is kept at 2 to 3 so that the purpose of warfarin is achieved without causing dangerous bleeding . When INR is raised then the dose is reduced or stopped completely. The purple patch that he has developed will go away slowly with time . But if bleeding from any other site starts like nose bleed then visit to hospital is must. I hope the answer was helpful. In case you need any further assistance , feel free to contact in writing. Regards Dr Talal Hussain