Warfarin

=Warfarin= = =

How it works
Works to thin your blood, preventing clot formation //Inhibits synthesis of vitamin K-dependent clotting factors (II, VII, IX, X) and the anti-thrombotic factors protein C and protein S.//

Questions to Ask
What medications? //Interacts with many medications, a few examples are: amiodarone, azole antifungals, carbamazepine, phenytoin, fibrates, macrolides, NSAIDs, SSRIs, tetracyclines, St. John's Wort, tramadol.// - medical conditions? - allergies?

How to take
Dose is variable, depending on INR - usually between 1mg and 10mg per day Take at the same time each day Stick to the same brand (have not been proven to be bio-equivalent)

Side effects
Bleeding: nosebleeds, coughing up blood, blood in urine/stools, bruising that doesn't heal quickly

Other advice?
Variability in dose: //dose may change depending on INR results// Non-bioequivalence of brands: //also that Coumadin comes in 1, 2, 5mg and Marevan comes in 1, 3, 5mg// Consistency in diet: //ensure that Vitamin K intake is consistent (green leafy vegetables)// INR: //aim between 2 and 3 for DVT prophylaxis// Interactions: //tell your pharmacist, doctor etc. that you are on warfarin//. Alcohol: //1-2 standard drinks per day is generally safe// Pregnancy: //Category D - may cause cerebral haemorrhage, underdevelopment of the baby's nose; possibly use heparin instead (does not cross placenta)//

CMI
[|Coumadin] [|Marevan] [|AMH] [|RGH e-bulletin: Patient education with oral anticoagulants] [|Australian Prescriber: Managing warfarin in the community] [|Warfarin Booklet: Living with warfarin - Information for patients] (convenient counselling/treatment card on page 26)