Blood-thinning medication (anticoagulants) such as warfarin can help reduce the risk of stroke for people with atrial fibrillation (AF). We asked people how they felt about taking warfarin. They told us their concerns about the increased risk of bleeding, attitudes to blood testing, self-monitoring, and the interaction of warfarin on diet and medication.
Increased risk of bleeding
While the association of warfarin with rat poison was rarely a deterrent, fear of bleeding and the inconvenience of regular blood tests to check INR levels (INR, or international normalisation ratio, measures how well your warfarin is working) were concerns for many people with AF.
One of the side effects of warfarin is an increased risk of bleeding. People we spoke to reported an increased tendency to bruise, cuts taking longer to stop bleeding, and a fear of falling and cutting themselves. Jenny mentioned how her husband knocked a small wound on his hand while on warfarin and bled profusely, and Nuala described “a lot of bleeding” when she had a tooth removed.
Gail’s face was “really swollen and bruised” after having dental work done while she was taking warfarin. Elisabeth Y’s decision not to take warfarin was influenced by the circumstances surrounding the death of Scotland’s first first minister, Donald Dewar, who had a “massive cerebral bleed” after falling and banging his head while on warfarin.
Geoff is concerned about bleeding when taking warfarin but balances this against his risk of stroke.
Ginny was advised to curtail her mountaineering activities while on warfarin because of the risk of internal bleeding.
Recently diagnosed with AF, Janet is uncertain about taking warfarin because of a pre-existing medical condition.
Some people we spoke to wore bracelets or tags or carried booklets to alert people to the fact that they were taking warfarin for their AF. Paul’s bracelet has his condition, blood group, name and date of birth on it. Raymond also wears an alert bracelet: “It tells everybody what’s happened to me, that I’m on pacemaker, that I’m on warfarin.”
Chris Y had a dog tag’ made to alert people to his AF in an emergency.
Vera carries a yellow booklet which includes details of her blood test results.
Attitudes to blood testing
Being on warfarin involves regular blood testing to check INR levels.
Dr Tim Holt explains the importance of managing warfarin levels through regular blood tests.
Some people we spoke to viewed it as a small inconvenience worth putting up with. Geoff, who has his blood test on the way to work, described how “it only takes 15 minutes and they give you a little pin-prick and they give you the results straight away”.
Glyn praised the “new machine” at his GP surgery which tested his blood with a finger-prick test and provided immediate results so that his doctor could adjust his levels of warfarin if necessary.
Vera explained the routine of blood testing since she started taking warfarin.
However, bruising from regular blood tests and the inconvenience of attending anticoagulation clinics or GP surgeries for blood testing were issues for others. Regular blood tests left Paul’s arm looking “like a pin cushion”. For Ginny, who lives in a rural area, regular trips to hospital to have her blood checked proved expensive and time-consuming, as well as interfering with her work.
Others also found the regular blood testing quite difficult to fit in with work commitments. Dave, whose job involves frequent overseas travel, described the prospect of being on warfarin and having regular blood tests as “seriously inconvenient and an awful lot of irritation” and decided not to take it.
Dot found the process “a drag” and “a big chunk of time and disruption every week”. Adjusting warfarin levels after blood testing could also be a problem.
James finds fortnightly blood tests interfere with his work. He finds the queues frustrating.
While recognising the importance of blood tests, David Y found trips to the hospital very time-consuming.
David X explained how adjusting warfarin dosage after blood tests could be confusing.
Home monitoring of INR levels
Home monitoring of INR levels can be a solution for those who find attending clinics for regular blood tests inconvenient. For some, home monitoring offered them increased independence and a sense of control in regulating INR levels.
However, self-monitoring was not always appropriate or freely available. Dot was told that she could self-monitor once her INR was stable so long as she bought the machine and testing strips herself.
Nuala would find it useful to self-monitor as “it would give me more independence”, but her medical team are less enthusiastic.
For Eileen home monitoring is a convenient way of testing her blood without going to the hospital.
Anne wants to be in control of her warfarin medication but has had to battle to get her GP to support this.
Interaction of warfarin on diet and medication
Some people taking warfarin talked about its interaction with certain foods and drink. They found foods such as cranberry juice and grapefruit, or going out for a big meal or a few more drinks than usual could affect warfarin. However, not everyone found it easy to identify the dietary cause of INR fluctuations. As Raymond said,”I don’t know what bit of the diet causes this to go wrong.” Nuala followed the advice of her doctor to “eat whatever you want and I’ll warfarinise you.” This has given her more freedom in dietary choices.
David X emphasised the importance of monitoring your intake of alcohol and green vegetables while on warfarin.
Anne has lost 10.5 stone. She talked about dieting and the effect that has had on her warfarin.
People we spoke to told us that prescription medicines and over-the-counter products such as antibiotics, ibuprofen, aspirin, cough medicine and vitamins could also interfere with their INR levels.