Warfarin

Drug Class:	Commonly Known As:	Category:
Anticoagulant	Marevan®	Adult

Warfarin - What is it for

Warfarin is an anticoagulant, sometimes called a "blood thinner”

Warfarin prevents clot formation and existing clots from getting bigger

Warfarin does not dissolve clots that have already formed as your body’s natural processes will dissolve the clots

We currently keep three strengths of warfarin as described below:

Do not change brands as they may have slightly different effectiveness

Why are you taking Warfarin?

You are prescribed warfarin by your doctor for:

□ Existing clots in the lungs, veins, arteries or heart

□ Irregular heart rhythm

□ Heart valve replacements

□ Stroke

□ Others: _____________

To reduce the clotting ability of your blood thus preventing further complications
Duration of treatment may vary from 3-6 months to long term depending on your condition

Unexplained nose bleed
Bleeding from gums when brushing teeth
Prolonged bleeding from minor cuts (10-15 minutes) despite applying pressure on wound. Action: Check with your doctor if the bleeding does not stop within 15 min or if you feel unwell
Excessive menstrual bleeding (women) Action: For women, increased menstrual flow is common but check with your doctror if you feel unwell.

Blood in urine or cloudy and dark urine
Black, sticky or tarry stool (not due to iron supplement)
Coughing up blood or coffee ground-like vomit
Unexplained large bruises or purplish area on skin
Sudden severe headache with nausea or loss of consciousness Action: Check with your doctor immediately or admit yourself to the Accident and Emergency Department (A&E) if you experience any of the symptoms or feel unwell

Effect of warfarin depends on the amount of Vitamin K in your body which is mostly derived from your diet
Eat a well-balanced diet while you are on warfarin
Ensure consistent and moderate consumption of Vitamin K rich food (Refer to the table at the bottom of this page)
Avoid making any MAJOR CHANGES to your diet (e.g. becoming a vegetarian) without first consulting your doctor or pharmacist
Avoid excessive alcohol consumption. It is advisable not to take more than 5 cans of beer or 1 bottle of wine per week
Avoid any form of traditional or herbal remedies and over-the-counter supplements (e.g. gingko, garlic, cordyceps and ginseng) as their effect on warfarin is unpredictable
Consult your doctor or pharmacist before you start or stop taking any medication or supplements. Certain medications like pain killers, antibiotics, and hormonal

Warfarin can be taken with or without food
Take at the same time, once daily
DO NOT miss, double or adjust your dose unless directed by your doctor or pharmacist

What happens when you start Warfarin

You will be given a booklet called Anticoagulation Therapy Record that provides an ongoing record of your blood tests and warfarin dosage
Remember to bring the booklet with you every time you visit Anticogulation Clinic
Warfarin dose is adjusted according to your desired International Normalised Ration (INR) that measures the effectiveness of warfarin and its bleeding risk
Your desired INR range is: _____________________
Blood tests may be required more frequently to determine the appropriate warfarin dose
Your dose may change after each visit depending on your INR result. Your doctor or pharmacist will inform you any dose changes
Inform your doctor or pharmacist of any illnesses, hospitalisation, changes in medication(s) or lifestyle at your next appointment
Inform other healthcare professionals (doctors, dentist, pharmacist) whom you are seeing for other condition(s) that you are on warfarin

Take it as soon as you remember if it is within 8 hours of your usual time to take warfarin
If it is after 8 hours, skip the dose for that day
Just take your warfarin dose at the usual time the next day
DO NOT take double doses, unless your doctor tells you to, as this can cause excessive bleeding
Record the dates on which you missed your dose(s). Inform your doctor at your next appointment

;#Keep away from children;#Keep in a cool, dry place, away from direct sunlight;#Store at room temperature;#

What else do you need to know about warfarin?

Inform your doctor if you have not been eating well or feeling unwell (e.g. fever, vomiting, diarrhoea, infection)
Avoid intramuscular injection because it may lead to haematoma (bleeding in the muscle)
Ensure that you keep sufficient warfarin supply at all times especially if you need to travel
If you are pregnant or intending to get pregnant, please inform your doctor as warfarin may affect your foetus

Do you need to make any lifestyle changes?

No need to make any changes to your lifestyle. Keep it consistent and have a well-balanced diet.
Be extra cautious when handling razors or other sharp objects
Avoid contact sports or other activities that may cause you to be injured and lead to excessive bleeding