NHS Foundation Trust
Information for Patients Warfarin Therapy Patient information for Warfarin therapy
Warfarin is used to reduce the risk of unwanted blood clots forming, or to prevent a current clot from getting any bigger.
Serious side effects:
These are rare, but can include bleeding and bruising for example: • Heavy nosebleeds (more than 10 minutes) • Blood in urine or stools • Large black bruises without injury • For women-increased bleeding during periods (or other vaginal bleeding). If you develop any of the symptoms you must seek medical attention.
Other side effects include: • Skin rash or yellowing • Nausea, vomiting • Diarrhoea • Reversible hair loss • If you suspect that taking Warfarin has caused any unexpected side effect you should talk to your GP.
Blood test for Warfarin:
This is called an INR (International Normalised Ratio) These are done either by: • Finger prick at an anticoagulant clinic led by a biomedical scientist • A venous sample from your arm which is processed by the laboratory. Your dose of warfarin will be adjusted depending on the INR results: • If the INR is too low the dose will be increased • if the INR is too high the dose will be decreased.
2 Following a dose change your INR will need to be checked one or two weeks later.
Therapeutic range and target:
You will be told your therapeutic range. Ranges are usually 2.0-3.0 (target 2.5) or 3.0-4.0 (target 3.5), but other ranges can be set by your consultant. Your consultant will also set the duration of your warfarin treatment.
Appointments:
It is important for your safety that you have the blood test on the date we give you. If you cannot attend on the date given, contact us at the anticoagulation office at Leighton Hospital to arrange another date.
If your sample is sent into the lab for testing you will receive your yellow book back by post, with an updated dose and next blood test date. We will contact you if there is a large change in your dose.
Once your warfarin level is stable, the time between your blood tests will increase.
Please telephone us at the office if you have any concerns.
Alert Card Please carry your Alert Card with you at all times. Not actual size
Front Back 3 Taking your tablets:
• Remember to take your tablets at the same time each day • Preferably some time after 6pm • Ideally on an empty stomach • If you accidentally forget a dose, do not take double the next day • If you think you have missed several days doses then telephone your GP or the Anticoagulant Practitioner for advice.
Repeat prescriptions should be obtained from your GP. Please take your yellow book with you when collecting your prescription from your GP and also when you collect your warfarin from the pharmacy.
Pain medication:
• Recommended: Paracetamol, Codeine, Co dydramol • Avoid: Aspirin and Ibuprofen or products that contain these.
Other medications:
It is important to continue taking all medications that have been prescribed for you by your Consultant or your GP. However, warfarin is known to interact with a large number of prescription drugs, over the counter medicines and herbal remedies. It is therefore important that you inform us of any changes in your medications as soon as you start them as you may need a blood test earlier than your next routine appointment.
Common medicines and supplements and food that interact with warfarin:
Medicines Antibiotics Non steroidal anti inflammatory drugs Antidepressants 4 Stomach ulcer medicines or acid reducing agents Lipid lowering agents Antifungal agents
Supplements Chondroitin plus glucosamine Ginseng Cod liver oil Green tea Coenyzme Q10 Horse-chestnut Feverfew Selenium + ACE Fenugreek St John’s Wort Ginger Vitamin A, C, E or K Ginkgo Willow
Diet:
• There is virtually no dietary restrictions • Eat a healthy well balanced diet and avoid strict or crash dieting • Avoid grapefruit juice and cranberry products.
If you are ill and unable to eat properly or if you suffer from a period of diarrhoea and/or vomiting that lasts more than two or three days please contact us.
Alcohol:
Alcohol may be taken in moderation only, no more than three units a day for men and two units a day for women. Exceeding this limit is likely to affect your warfarin control and could put you at risk of bleeding. • One pint of cider is 2.8 units • One pint of lager is 2.8 units • One pint of bitter is 2.8 units • Alcopops are 1.4 units • Single spirit measure is 1 unit • Small glass of wine (125ml) is 1.6 units 5 • Large glass of wine (175ml) is 2.1 units • Bottle of wine is 10 units. (data provided by NHS Choices http://www.nhs.uk/Tools/ Pages/Alcohol-unit-calculator.aspx?Tag=Alcohol)
Pregnancy:
• If you find that you are pregnant you must STOP taking warfarin and seek advice from your GP immediately • If you are thinking of starting a family please discuss this with your GP.
Travel:
We advise that you have an INR check before any overseas travel. You may also need to have your INR checked while you are away. This is for your own safety.
It is recommended that you have valid medical insurance for your trip and that you take sufficient warfarin for your stay.
Help us to help you:
If you need advice about your anticoagulant treatment or do not understand the dose instructions you have been given, please contact us. Never be afraid to ask us any questions you may have. Remember the advice we give is dependant on the information we have about you.
Please advise us: • If you have any bleeding or bruising • If there are any changes in your medications; new drugs that you are taking or other drugs that you have stopped. This includes any you may have bought yourself, including herbal remedies • If you have missed any doses of Warfarin, we need to know how many days you missed and when you missed them 6 • Appointments for any operation or dental treatment • The dates you are going on holiday and how long you will be away • If you move, your new address and telephone number • If you change your GP practice, the name of your new GP.
Please note that the Anticoagulant staff are unable to discuss with you the medical condition for which you have been prescribed Warfarin. If you want further advice or information about this you should talk to your GP.
References:
The Pharmaceutical Journal (Vol 280) 31st May 2008 pp.662-663
Living with Warfarin published by Anticoagulation Europe (UK) accessed 2009
BJH 130,777-780. 2005
Oral Anticoagulant Therapy published by NPSA 2007
Drinks of Britain, units. They all add up. Published by Department of Health
Leighton Anticoagulant Service 01270 273285 from Monday to Friday 9.00am-5.30pm
Or you can leave a message on the answer machine and we will call you back.
In an emergency contact your GP or the nearest A&E department.
7 This leaflet has been reviewed by the Readers’ Panel May 2009.
This leaflet is available in audio, Braille, large print and other languages. To request a copy, please telephone 01270 273285.
Leighton Anticoagulant Service Leighton Hospital Middlewich Road Crewe, Cheshire CW1 4QJ www.mcht.nhs.uk Direct Line: 01270 273285
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IMPRESSIONS DESIGN & PRINT 01270 767661
Reprinted July 2016 • Review July 2018 • Ref: DCS/ACOAG/0010716