Pradaxa vs. Warfarin: Should Cardiac Patients Worry?

Pradaxa vs. Warfarin

Recent news about the possibility that the relatively new blood clot preventing drug Pradaxa has been associated with an in increase in heart attacks can lead to confusion for cardiac patients over whether they should be concerned that their doctor is prescribing Pradaxa over its time-tested competitor Warfarin. In some ways comparing Pradaxa vs. Warfarin is like comparing health news sites—some have slightly more or different benefits than others. Presented here is a synopsis of Pradaxa vs. Warfarin views and a link to a cardiac specific article that presents a more detailed discussion that provides cardiac patients a clearer understanding of whether they should worry about whether they are taking Pradaxa over Warfarin.

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One way to look at the Pradaxa vs. Warfarin news is that it is partly about the Latin phrase “primum non nocere.” “Primum non nocere” is just one of several fundamental medical ethics originating from the Hippocratic Oath that plays an important role toward providing healthcare that is both safe and beneficial to patients. It is more commonly known by its “First, do no harm” interpretation that comes from a rough Greek translation of “I will prescribe regimens for the good of my patients according to my ability and my judgment, and never do harm to anyone.”

Another way to look at the Pradaxa vs. Warfarin news is that it is also partly about the history of the drug Warfarin. Warfarin has been used successfully for several decades as a blood thinning medication important to patients with cardiac problems and other medical conditions where the threat of a life-ending blood clot exits. Some will argue that it is safer to stick with a medication that you know works, even though it may not work perfectly all the time. Warfarin for example, is known for presenting side effects like uncontrolled bleeding.

Pradaxa, on the other hand, is a new kid on the block blood thinning agent that shows promise as a potential replacement for Warfarin. Its history, however, is thus far very recent and health officials are cautious about whether it is truly a better choice over Warfarin. News reports of seemingly conflicting studies were published recently stating that Pradaxa both, may or may not be linked to an increase in heart attacks in comparison to Warfarin and other blood thinning drugs.

In a nutshell, both studies looked at Pradaxa from different viewpoints both data-wise and underlying cardiac condition-wise. It’s kind of like doing a taste test comparing apples and oranges and asking if one is sweeter than the other—it depends on the parameters of what is measured and what you mean by “sweeter.”

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A third way to look at the Pradaxa vs. Warfarin news is that it is also partly about the money: Whichever blood thinning drug “wins” as the better of the two, will result in earnings for its maker, shareholders, sales reps, etc. And of course, this is cause for justified concern. Pradaxa is not the first drug heavily marketed to consumers as a drug of choice, nor will it be the last. Another Latin phrase “caveat emptor” - buyer beware, is warranted here as well.

Fortunately, a cardiac-specific and WEBMD owned theheart.org has recently published an online study that indirectly addresses the aforementioned views and provides for the reader a more comprehensive take on the two studies that appear at odds with each other over the Pradaxa vs. Warfarin question. In it, the cardiac patient reader will find some reassurance that the authors from both studies do not see each other’s results in conflict, and agree that further study is needed to determine which drug is the better and under what condition parameters.

Right now it looks like it’s a tie.

Image credit: Courtesy of Wikipedia

Source: The Heart.org— Dabigatran: New data on MI and ischemic events

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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 (after receiving medical treatment) consult with an attorney who is experienced in handling such a matter. - Paul Paul J. Molinaro, M.D., J.D. Attorney at Law, Physician