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 atrial fibrillation (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.
Geoff is concerned about bleeding when taking warfarin but balances this against his risk of stroke.
Age at interview: 69
Sex: Male
Age at diagnosis: 60
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The only thing about warfarin is yes, it’s I suppose it is a slight concern that if you do get injured and you start bleeding somewhere, it could be in a, I don’t know, car accident or anything, you know, it could be potentially fatal because you bleed so fast. Unless people realise you, you know, you could be in trouble. But it’s all a question of risk and weighing the chances of getting a stroke or whatever.
The warfarin is a nuisance because you bleed so easily, and you cut yourself, as I did the weekend, and I’ve still got a plaster on because I couldn’t stop the thing bleeding, and it was quite a deep cut. And I was thinking I’d have to go to A and E, dare I mention it, to try and get it sorted but it did eventually stop. But that’s a slight worry, you’ve always got to take plasters round with you in case you cut yourself or something like that and it’s obviously a risk.
Ginny was advised to curtail her mountaineering activities while on warfarin because of the risk of internal bleeding.
Ginny was advised to curtail her mountaineering activities while on warfarin because of the risk of internal bleeding.
Age at interview: 49
Sex: Female
Age at diagnosis: 45
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Now I seem to be somebody who needs to escape before an operation, I need to escape particularly with this mountaineering and it sort of puts me in good stead to go through an operation. And the doctors realised this but I was on warfarin and he said, “Well.” I said to him, I said, “Well, how bad a bruise have I got to have before I go to hospital.” You know, thinking, you know, bruises, external bruises. Not being medically trained, it never occurred to me that his reply was, “Well, we’re not so worried about that but what we’re worried about is internal bleeding.” So he said, “If I was you, I’d put your more adventurous mountain activities on the back burner, while you’re on warfarin.” And I thought, “Right. Okay.”
Recently diagnosed with AF, Janet is uncertain about taking warfarin because of a pre-existing medical condition.
Recently diagnosed with AF, Janet is uncertain about taking warfarin because of a pre-existing medical condition.
Age at interview: 74
Sex: Female
Age at diagnosis: 74
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I know that it can cause fairly excessive bleeding if they don’t get the levels right and I also have another medical condition that if I if I did bleed a lot it would give me a lot of concern and because that’s sort of in remission at the moment and I’m feeling quite fit and healthy, in a way, I’m quite reluctant to disturb all that.
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.
Chris Y had a ‘dog tag’ made to alert people to his AF in an emergency.
Age at interview: 64
Sex: Male
Age at diagnosis: 62
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Well, this is what I made for myself [shows dog tag on chain around neck], which is like a dog tag, which has my name, date of birth, blood group and that I’m on warfarin, so that if I’m involved in an accident or something, then the medics who get to me can, hopefully, save my life [laughs]. Ah, but at least they’re aware that I’m taking warfarin. I have an alert card in my in my wallet that I carry around, but I thought this was probably a bit more immediate, you know, and so I’ve got, you know, I wear this whenever I go out.
Vera carries a yellow booklet which includes details of her blood test results.
Vera carries a yellow booklet which includes details of her blood test results.
Age at interview: 75
Sex: Female
Age at diagnosis: 74
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Yeah, you have to keep it with you at all times and it it’s got your name and your doctor’s surgery and everything on it, name and address, that sort of thing, and every time you go for a blood test they record in it what the reading was for that particular time, and what dosage you’re on. So if you keep it with you at all times, if you happen to be in an accident it it’s handy in your handbag, and it’s yellow so it does show up. That that’s what it’s for. We did get another yellow bigger pamphlet telling you all the things, which I’d already got in the leaflets from the doctor anyway, but I always remember to keep that little yellow booklet with me.
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.
Dr Tim Holt explains the importance of managing warfarin levels through regular blood tests.
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They need to manage the anticoagulation carefully in order that the, in the case of people taking warfarin, that the thinness of the blood is kept within the limit. That’s very, very important because the risk of stroke is there if the person is not taking warfarin or if the warfarin dose is too low but it’s also possible to have the other type of stroke, which is caused by a bleed into the brain, if the warfarin dose is too high. So keeping in close touch with the medical team, whether it’s the general practice or the specialist at the hospital, is important to keep the condition controlled and the stroke risk minimised in the in the long term.
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 fifteen 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.
Vera explained the routine of blood testing since she started taking warfarin.
Age at interview: 75
Sex: Female
Age at diagnosis: 74
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Anyway, I looked at all the things and I looked talked it over with one of my sons and he said, “Well, do what you feel best.” So I decided to start the warfarin. So I had another long form about that to look at and he started me off, gave me a prescription for all the different strengths straight away, and so I was able to pick them up from the chemist’s straight away. And I had to take one that day, one the next day, both in the evening and go back the next morning for a blood check, blood test. And that was sent through to the hospital in [town name] and they said, “They’ll be ringing you this evening to tell you what dose to take from now on.”
That happened for two weeks, I had to go for a blood test for two weeks and then they said, the doctor said, “Now you can have just the finger prick test.” So I do that now. Sometimes I go once a week, sometimes its two weekly, but this time it’s been not for a month, and I do try and remember to take whatever dose it is about six o’clock in the evening. I’m not always spot on the ball with that but in in the evenings. And I was warned not to try not to cut myself because I would bleed much more easily, and so far I haven’t.
I mean it’s a bit of a bother sometimes thinking, “Oh, I’ve got to go for another blood test.” But I’m in and out so quickly, especially when it’s just a little finger prick. It’s amazing, you know, you, a little drop of blood goes onto this thing and onto the machine and works it out, and then I get a print out of what the dosage I’ve got to take for either the next week or whatever, and given an appointment then for the next time.
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.
James finds fortnightly blood tests interfere with his work. He finds the queues frustrating.
Age at interview: 63
Sex: Male
Age at diagnosis: 59
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One of the issues I have is my warfarin, getting maintaining my INR levels and they, warfarin just doesn’t seem to give a constant control of my INR, and so I’m forever going back to the hospital, back to the doctors to have a another test, so I’m going on a fortnightly basis now. Which does interfere with my work and it does annoy me that I try and get a first thing in the morning appointment, and I can’t have a first thing in the morning appointment because there’s loads of pensioners that are getting there at eight o’clock and you’re queuing behind them and it’s most frustrating.
While recognising the importance of blood tests, David Y found trips to the hospital very time-consuming.
While recognising the importance of blood tests, David Y found trips to the hospital very time-consuming.
Age at interview: 67
Sex: Male
Age at diagnosis: 64
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Well, I found I found it to be an interference really with your day to day life, although at the back of that, knowing full well that I was doing that because my health was at risk, and I needed to as a matter of as a matter of it was compulsory and not, you know, not something I felt I will or won’t do whenever. No, it was it was an interference because of going to hospital and it it’s very, it’s very time-consuming as well because the local hospital, you’ve got to allocate yourself three hours. That’s from the time of getting there to the time you come away because instead of having a separate anticoagulant clinic, it’s got like, I called it Dracula’s reception, everybody from every clinic goes there and just takes a raffle ticket and really, you know, it takes a long time.
David X explained how adjusting warfarin dosage after blood tests could be confusing.
David X explained how adjusting warfarin dosage after blood tests could be confusing.
Age at interview: 73
Sex: Male
Age at diagnosis: 61
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I had to take quite a high dose of warfarin before my INR reading was at the level that was deemed safe. And the problem with that, you see, is not only do you have to gradually adjust the level of warfarin based on the information in the letter from the hospital, but you have all these different tablets to take, and sometimes you have to split one to get it right. And then you move up the next week, again it may not be quite right, so you have to drop these and take one of another size or combination of sizes. You get the tablets in ones, twos and fives, so you’ve got the combination problem. Now anyone who is really elderly could find that, I would have thought, very difficult.
* Text altered with David’s wishes.
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.
For Eileen home monitoring is a convenient way of testing her blood without going to the hospital.
Age at interview: 63
Sex: Female
Age at diagnosis: 53
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It’s quite difficult to get stabilised and you have to have blood tests frequently, to make sure it’s all right. I got a machine, so with the hospital’s permission, I could do it myself and I just ring them up with the results and so that I don’t have to go up to the hospital.
Is that because you’re a nurse?
No, anybody can do it. If the hospital assesses that it’s not going to freak you out or something. Anybody can do it. In fact, I first saw it advertised in the in the clinic, where you, you know, the haematology, anti-coagulant clinic was where I first saw the machine advertised and I’d been to several of the AFA conferences and had seen it there and wondered about it. Then, when I saw it advertised in the clinic, but no, you don’t have to have any medical knowledge at all.
Anne wants to be in control of her warfarin medication but has had to battle to get her GP to support this.
Anne wants to be in control of her warfarin medication but has had to battle to get her GP to support this.
Age at interview: 71
Sex: Female
Age at diagnosis: 70
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But I want to be in control of it myself. The nurses are busy up there. They don’t seem to be, I don’t know, they made a mistake a few times. They’ve, when it started to settle down, they said, “Oh good, we don’t need to see you again for six weeks.” This had only been one reading that had been stable. So I feel much safer doing it myself but I asked them, they said, “Oh no, no, no.” I asked the GP and they said, “Oh, we’re not allowed to.” And they read, the GP read me out something from the primary care trust or whatever it’s called nowadays saying, you know, “[local area] GPs must not get involved with people self-medicating.” Which seems so stupid because it’s going to be a hell of a lot more costly dealing with residents with strokes than, you know, than spending a bit of money on the on the strips and the needles.
Anyway, I have pushed it and pushed it and pushed it and now, it turns out, that yes, [local hospital] has got a programme all set up that if people are persistent and they buy their own and they buy their own strips, then they can monitor them and test the machines every now and again, perfect. But it’s been a battle getting as far as this to find out that, actually, yes, if I do go and buy it, I will be supported with it. It’s really been a battle getting that information. Nobody was going to volunteer it.
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.
David X emphasised the importance of monitoring your intake of alcohol and green vegetables while on warfarin.
Age at interview: 73
Sex: Male
Age at diagnosis: 61
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You’ve got to be very careful of your alcohol intake. You also have to be careful as to the green vegetables that you eat. So your diet is affected. Because vitamin K is the antidote to warfarin, this dictates you have to be very careful of your green vegetable consumption. I had, at one conference, a long conversation with a couple of doctors and I said, “Well, what I do is to set myself a certain amount of broccoli, for instance, per week, and I balance that against the warfarin information that I’m getting back from the hospital, to try and ensure that I balance my diet with what the warfarin readings need to be.” Because it can be very difficult. The warfarin levels can vary so much. If you go out for a meal or if you eat out a lot, it must be very difficult to keep your warfarin levels correct.
* Text altered with David’s wishes.
Anne has lost 10.5 stone. She talked about dieting and the effect that has had on her warfarin.
Anne has lost 10.5 stone. She talked about dieting and the effect that has had on her warfarin.
Age at interview: 71
Sex: Female
Age at diagnosis: 70
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I lost ten and a half stone. I went from nearly twenty two stone to ten and a half. I mean gradually it comes back and then I do it again, just to keep it sort of, I can cope on sixteen stone. I’ve been that for many, many years but, when it gets to nineteen and so on, really struggling and, of course, breathless. So everything, you know, becomes rather confusing as to what’s causing what. And the warfarin is a terribly bad regime for that because it immediately is thrown out and, you know, out of sync and you have to keep on going back and being checked and have the warfarin levels changed and so on.
But any variation in your diet, antibiotics, anything can throw the warfarin levels out, and I find it very unnerving.
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.
Describing warfarin as her ‘pet hate’, Mary talked about the incompatibility of warfarin with some prescription and over-the-counter medications.
Describing warfarin as her ‘pet hate’, Mary talked about the incompatibility of warfarin with some prescription and over-the-counter medications.
Age at interview: 84
Sex: Female
Age at diagnosis: 84
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I’ve had this cough lately. And I was coughing all night. I was going, I was sick with it and I wasn’t I couldn’t take cough linctus because it wasn’t. I asked the chemist. I asked the doctor, “No, no just a simple glycerine and lemon. You cannot have anything stronger.” But, when I started being sick with this cough, the doctor gave me a linctus with codeine in it and that has helped a lot that linctus but this, you know, it’s, you’re supposed to show it to the chemist whenever you buy anything, any drugs or medicine. So it’s very or I find it’s it ties me down a bit.
It ties you down. In what way?
Well, I can’t choose what drugs to have. I mean I used to take zinc. I used to take ginkgo biloba for memory, all sorts of things now I can’t.
And I’ve got to give up all those, all my vitamins. I suppose I could go through them with the doctor to see what I can take and what I can’t but it’s so time consuming I just get, they say, “Don’t take any more. That’s it.”
Richard found that he was no longer able to take medication such as ibuprofen or aspirin when he developed a bad back.
Richard found that he was no longer able to take medication such as ibuprofen or aspirin when he developed a bad back.
Age at interview: 56
Sex: Male
Age at diagnosis: 52
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The main hassle is there are some medications you can’t take particularly ibruprofen and those sort of things, which would have been very helpful for my back. And I used to, when I had back problems years ago, I used to take them and they were quite good.
Can’t have aspirin but can have you can have paracetamol for sort of headaches, that kind of thing but I always used to take aspirin before and aspirin always seemed to work better for me than any of that stuff. So it it’s things like, you know, I probably would have, given the back thing, I would have been trying ibuprofen, glucosamine and things like that, just that kind of thing. And I can’t do that, any of that.
(For more see ‘
Atrial fibrillation, stroke risk and blood thinning medication’ and ‘
Alternative to warfarin for atrial fibrillation: the new anticoagulants’).
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