WARFARIN PATIENT EDUCATION AND ADVICE What is Warfarin? y Anticoagulant helps prevent clots in the blood from forming Uses y Prevention of DVT / PE, use in people with heart valves , AF or atrial flutter, stroke/TIA How does it work? y Vitamin K antagonist for blood factors made in the liver How long does it take to work? y It starts working after 24hrs but does not get full effect until after 72-96hrs need to use heparin for the first 4-5 days y A single dose works for 2-5 days however it is important to take the doses as prescribed to maintain the correct level in the blood What dose do I take? y 5mg is usual starting dose (3mg if elderly or malnourished or liver failure or CCF ot high INR to begin with) y Most people start on 5mg once a day for the first 2 days and this dose is altered according to a blood test called INR. This blood test basically measures how thick/thin your blood is. We want your INR to be somewhere between 2-3. (or 2.5-3.5 if valve) y Daily INR until 2x consecutive days within therapeutic range and then every 48hrs , adjusting the dose to maintain within therapeutic range... y If the INR is too low = thick blood y If the INR is too high = thin blood y You will not know that the INR is too high or too low and therefore you need to have INR blood tests very regularly at the beginning to make sure it stays within the normal range Blood tests and monitoring y Daily every 2 nd day every few days weekly eventually every month What about drug interactions? y There are many drug interactions macrolides, steroids, antibiotics, amiodarone there are many!! y Always let your pharmacist know when getting OTC meds y Always tell doctors you are on it some people like to have a medical alert bracelet for this purpose y Never take alternative medicines unless you are sure they will not interact St Johns Wort commonly reduces the effect of warfarin greatly, Ginkgo increases Missing a dose y Take as soon as you remember if on the day you were meant to take it notify your dr y If you have missed a dose and forget to take on the day dont take extra on the next day just take the usual dose Medications you should AVOID; y NSAIDs and aspirin y Vitamin K, C, E and other high potency vitamins multivitamins are OK if low potency y Certain laxatives ask pharmacist y Antacids just before taking warfarin Mylanta etc Foods and Warfarin y Cruciferous veges y etOH y Liver Dont make drastic changes to your diet everything in moderation