Anticoagulation UK

Warfarin or the new Anticoagulants Xarelto (Rivaroxaban) or Pradaxa (dabigatran)

Many of you who read my blogs know I keep banging on about your therapeutic range, which is measured in percentage of times your are within your range and The Gold Standard is 60%. At your next INR visit, why not ask your provider what your percentage is, it might surprise you. For those with excel can get a free spreadsheet that automatically works out your therapeutic range.

A new study published in the March 2012 American Heart Journal looked at whether the Pradaxa® medication or warfarin was more cost-effective for you. The study found that if you can keep your time in INR (International Normalized Ratio) target range at or above 73% - warfarin is a more cost-effective choice for patients.1

How do you keep your test results in range at or over 73%? The answer may be weekly self-testing. Several studies have shown that by testing weekly (even if you are a stable warfarin patient) you can improve your time in range. 2,3 Weekly testing is practical and easily done by patients who self test in the privacy of their home. Share with your doctor your desire to self test as self testing begins with a prescription.

This confirms my personal opinion on weekly self-testing and self-dosing for those who are capable. Would like to hear other views, so please keep blogging.

6 Replies

I can concur with Firemansam as I have been self testing for around 13 years, have tested on a weekly basis for almost all that time and record an INR within my therapeutic range of 3.0 to 4.0 94% of the time. I am certain that weekly testing helps to keep you in range but would hate to have to make a weekly test to the anticoag. clinic.


I think after a certain amount of time u can kind of gauge u're INR, 4 example I know whether it's too thin or thick as 2 how I'm feeling in myself. Many a time a GP has told me 2 alter my dose & I've thought 'u silly man, if I do that my INR is gonna go sky high!' so I'm all 45 self managing if u know what u're doing. Unfortunately can't self test as they want me 2 pay 4 the machine which I think is crazy: if u're on lifelong anticoagulants, surely it's more cost effective 4 them 4 people 2 self test as u're not taking up appointments 2 have u're blood done, samples don't have 2 b sent 2 the lab etc.


Hi Sher78,

If you review the poll on self-testing only 27% said it was the cost of the monitor was an issue. Have you spoken to any of the companies selling INR monitors and asked what special rates they do and you may find you can pay monthly and they are very cheap now days and well worth the investment for peace of mind. Make sure your GP will provide the test strips and you may have to justify your reason why you wish to self-test.

To take advantage of Self-dosing requires you to be able to self-test your INR after about 3 days to ensure you are in range and not too high or too low. You don't say what your percentage of INR tests are in range? This would give us a better understanding of your therapy. What percentage is your therapeutic time range, which is an important part of knowing if your warfarin is working to it's maximum effect.

Don't give up on self-testing and obtaining the monitor on the NHS, I know that it's something ACE is investigating at this time.


I'd say I'm in range almost 95% of the time, the only time I tend 2 blip is when I'm taking antibiotics etc, or going mental on my veggies which I know is gonna push my INR out. I think only once in the last 15 years has my INR gone mad & I haven't been able 2 account 4 it. The cost is a very big deal 4 me as I had 2 give up my job last year due 2 SLE & all the secondary malarkey that comes with it & have been classed as unfit 4 work until further notice but unfortunately apart from DLA, I only get a small amount from ESA, no other benefits as I have a partner who works full time & 2 young kids. My GP would provide the strips (have already asked about this) but the surgery cannot provide the machines. Have asked my rheumy but he says as this is a Haemo matter, I have 2 go & c them & trying 2 get an appointment with them 4 no other reason but 2 ask anbout the kits is impossible. Think I will have 2 badger my rheumy at next appointment ;0)


Cost is one issue... ease of use, another... and safety a big issue!

The prescription drug Pradaxa (dabigatran etexilate mesylate) is a medication which has been prescribed to hundreds of thousands of patients to thin their blood thereby reducing the risk of stroke and blood clots when they have certain underlying heart disease such as atrial fibrillation or heart valve problems, but not artificial heart valves. On December 19, 2012, the United States Food and Drug Administration issued the following Safety Communication about Pradaxa: “The U.S. Food and Drug Administration (FDA) is informing health care professionals and the public that the blood thinner (anticoagulant) Pradaxa (dabigatran etexilate mesylate) should not be used to prevent stroke or blood clots (major thromboembolic events) in patients with mechanical heart valves, also known as mechanical prosthetic heart valves. A clinical trial in Europe (the RE-ALIGN trial) was recently stopped because Pradaxa users were more likely to experience strokes, heart attacks, and blood clots forming on the mechanical heart valves than were users of the anticoagulant warfarin. There was also more bleeding after valve surgery in the Pradaxa users than in the warfarin users.”

Warfarin (Brand names include Coumadin, Jantoven, and Uniwarfin) has been on the United States market since about 1954. This well-known anticoagulant continues to be commonly prescribed to patients who are at risk of blood clots which can lead to serious consequences such as stroke and death. While warfarin has been time-tested and proves itself to be quite effective, and relatively safe (“safe” based on a risks and benefits analysis which considers the serious consequences of not anticoagulating patients at high risk of clotting). To maintain safety while taking warfarin , a patient must allow blood levels to be tested about every three months (to make sure there is not too much or too little in a patient’s system) and avoid foods which contain Vitamin K (such as many leafy green vegetables) which can render warfarin ineffective. Failure to take warfarin exactly as prescribed and to monitor warfarin levels can lead to uncontrolled bleeding which if not treated emergently can cause a patient to bleed to death. Fortunately, there are several antidotes to warfarin toxicity – all of which are commonly available to healthcare professionals. Antidotes include injectable Vitamin K, plasma (fresh frozen or cryosupermatant plasma), prothrombin complex concentrates, and recombinant factor VIIa.

One of the big “selling” points for Pradaxa as opposed to warfarin is that the patient taking Pradaxa does not have to submit himself or herself to regular blood draws and dietary restrictions. What promoters of Pradaxa conveniently do not tell physicians and patients is that there is no commonly available antidote for a Pradaxa overdose. Thus, should a patient’s Pradaxa levels reach a toxic level, he or she has a good chance of bleeding to death while physicians watch helplessly. Pradaxa levels are effected by advanced age, renal (kidney) function, extremes in body weight, and drug-drug interactions (aspirin, ibuprofen, nonsteroidal antiinflammatory drugs, and many other drugs commonly used by patients). In addition, should a patient on Pradaxa require emergency surgery (as a result of a motor vehicle accident, for example), he or she will be subject to uncontrolled bleeding and have a poor chance of successfully undergoing surgery. According to the National Center for Biotechnology Information, “In early 2013, there is still no routine coagulation test suitable for monitoring these patients; specific tests are only available in specialized laboratories. In early 2013 there is no antidote for dabigatran, rivaroxaban or apixaban, nor any specific treatment with proven efficacy for severe bleeding linked to these drugs. Recommendations on the management of bleeding in this setting are based mainly on pharmacological parameters and on scarce experimen-Haemodialysis reduces the plasma concentration of dabigatran, while rivaroxaban and apixaban cannot be eliminated by dialysis.”

In the last few years, several thousand patients, who have suffered serious injuries including death, have sued Boehringer Ingelheim Pharmaceuticals, Inc., the manufacturer of Pradaxa for failing to warn patients and their physicians about the serious adverse events that may result from taking Pradaxa. Many of these suits also allege that Boehringer promoted Pradaxa as being safer than warfarin.

If your physician has prescribed Pradaxa for you, you should immediately discuss whether there are safer alternative drugs for you. After weighing the risks and benefits, you and your physician can determine what drug is best for you. If you have taken Pradaxa, and have suffered uncontrollable bleeding, you should contact an attorney with experience in handling such lawsuits.

- Paul

Paul J. Molinaro, M.D., J.D.

Attorney at Law, Physician


What about Xarelto/rivaroxaban. Is this med contraindicated with patients with APS and on hydroxcholoroquinine? Should patients on Xarelto be tested or monitored?