Pradaxa: Better, Safer and Simpler than Warfarin?

Pradaxa, generic name dibigatron, has the potential to change the way we manage atrial fibrillation to prevent stroke.  Stroke is one of the most feared medical problems for many patients, and atrial fibrillation is one of the biggest risk factors for stroke.  Stroke is the third leading cause of death in the U.S. and the leading cause of long term disability.  Having atrial fibrillation increases a person’s risk of having a stroke about five fold and is the cause of 15-20% of strokes in America, over 100,000 strokes a year.   Most patients with atrial fibrillation are candidates for long-term anticoagulation, and until Pradaxa was approved by the FDA in October, 2010 patients were either treated with oral warfarin, injectable low molecular weight heparin, or with less effective anti-platelet medications like aspirin.

Warfarin has been the choice of most physicians and patients for prevention of stroke in patients with atrial fibrillation because it works well.  The annual risk of stroke in patients with atrial fibrillation is 4.5% without warfarin anticoagulation, and 1.4% with warfarin treatment.  This risk varies a great deal from individual to individual depending on associated risk factors like coexisting hypertension, diabetes, congestive heart failure, prior TIA or stroke and age over 75.  A scoring algorithm called the CHADS2 score is often used to better assess an individual’s risk.   For most patients the absolute reduction in risk of stroke is high enough that most physicians have encouraged most of their atrial fibrillation patients to take warfarin.  Warfarin therapy is no small undertaking though and has very significant bleeding risks. Several major problems are involved with use of warfarin as an anticoagulant:

  • A patient has to wait several days for the anticoagulation effects of warfarin to take effect.  During this time the patient needs to be tested frequently, sometimes daily, to assess whether the prescribed dose of warfarin is just right.
  • It often takes one to several weeks to get the dose just right.  Then after the INR is just right they will still need monthly blood tests to assure they remain adequately but not overly anticoagulated.  If this sounds like a big hassle and expense you are very perceptive.  It is.
  • Many drugs interfere with warfarin metabolism and so drug interactions are notoriously difficult to manage in patients on warfarin.
  • Because Warfarin is a vitamin K antagonist dietary variation in vitamin K content can have a significant effect on the anticoagulation effect of warfarin.
  • The therapeutic window for warfarin dosage is quite narrow, meaning the difference in dose between not enough and too much can be quite small.  It is very difficult to predict what dose an individual patient will need.

Pradaxa is approved by the FDA for treatment of atrial fibrillation at a single fixed dose for most patients.  It is dosed at 150 mg twice daily, and is effective within hours of taking the first dose.  It works at least as well as warfarin to prevent stroke in patients with non-valvular atrial fibrillation, and overall the Pradaxa side effects profile is generally lower than with warfarin.  In addition Pradaxa has far fewer drug interactions than warfarin which is notoriously affected by both diet changes and innumerable other medications.  Bleeding risks with Pradaxa seem to be about the same overall as with warfarin.  There may be a minimally lower risk of major cerebral hemorrhage and a higher risk of gastrointestinal bleeding with Pradaxa vs. warfarin.

The big issue holding back the widespread use of Pradaxa seems to be its cost.  In a recent cost effectiveness analysis in the Annals of Internal Medicine for use in patients age >65 with non-valvular heart disease, assuming a daily cost of Pradaxa at $13.60 the conclusion was that Pradaxa has incrememtally higher costs and incrementally higher added years of life.  Currently Pradaxa costs $230./ 60 doses , ie. 30 days supply or $7.66/day at Costco.com.  With this lower cost than assumed in the study it seems like Pradaxa may win in the cost effective analysis.

I believe this study takes into consideration the lower risk of cerebral hemorrhage complications that can often lead to very expensive hospitalizations and long term nursing home care with Pradaxa.  When I talk with other physicians they generally tell me that they would rather deal with GI bleeding, which is slightly more common with Pradaxa, than with intracranial bleeding which is slightly more common with warfarin.    I’ll be interested to see more post marketing cost analysis comparisons as they become available, and to see how many patients are switched from warfarin to Pradaxa, and how many new patients are started on each of these medications.

I will not be surprised if as more physicians gain experience with Pradaxa, and more cost analysis is done, that Pradaxa will become the standard of care for treatment of atrial fibrillation for stroke prevention in patients at high enough risk of stroke to warrant the risks of therapy.

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83 Responses to Pradaxa: Better, Safer and Simpler than Warfarin?

  1. Mike: The serum half-life of Pradaxa is 12-17 hours. That means that within about 2 days of taking a dose the amount left in the bloodstream is down to less than 1/8 to 1/16th of the maximum concentration after a dose. Conversely, because Pradaxa works directly, it works almost immediately after taking a dose. That means after a surgery or procedure a patient may need to wait until the risk of post-op bleeding has past to resume. This can vary by procedure, so discuss it with your physician. DrP.

  2. I had a colonoscopy some days ago and I didn t take Pradax for 5 days before the intervention when have been took out 2 polyps.

    After the intervention no blood in stool. After 2 days I start taking Pradax and start showing up trace of blood in my stool.

    It was probably too early to start taking pradax again ?

    How long last Pradax in the body after stop taking ?

    Thanks

    Mike

  3. Dana: Pradaxa, warfarin and the other direct anticoagulants, Eliquis and Xarelto are all options for patients being anticoagulated for stroke prevention from a-fib, but currently only warfarin and Xarelto have FDA indications for DVT/PE managment. You should meet with your boyfriend’s doctor to discuss which alternatives are optimal for him. Good luck. DrP.

  4. My boyfriend is on warfarin and they can’t get his blood count right.. so, I seen pradaxa commercial on tv. It sounded good at the time.. meanwhile we are reading and looking at this page and now we’re not sure on what to do or think…… we know you can’t give out medical advice and we understand… but we would like to know facts on this….. I mean you are wanting people to use this drug but I’m not seeing any answers why they can use this drug and feel safe….

  5. You forgot to tell your reader that PRADAXA doesn’t have a antidote , if you start to bleed you can bleed to death. Older people who fall and say bump their head , a small bump on the head and they can bleed to death. I have personally took pradaxa around three weeks , lost 4 units of blood was out 27 minutes and now have a pacemaker and defib install in me to keep me alive, three weeks earlier I was playing major softball in a world tournament. So every one should know this drug does bury it miskates

  6. Lis. Accupuncturist: Your comment is rambling and I’m not sure what your point is except that Phara is trying to make money. Aspirin has been shown to be much less effective that anticoagulation with warfarin for stroke prevention. Pradaxa although it has no antidote has a relatively short half life, can be dialized, and I feel plays a role for some patients with a-fib. Why not try aspirin first? Because it does not work well. Are you suggesting to put patients on aspirin until they have a stroke first? DrP

  7. Forgot to add, regarding PRADAXA, or reiterate another’s posting, it is number one in deaths last year. Great how FDA has no problem rushing these drugs to market (remember, Pradaxa is maybe two years old, fills $10-20 Billion estim. mkt), and tries to take ownership of vitamins or minerals, and outlaw natural herbs like Ma Huang (Ephedra) which are VERY GOOD, because some baseball player works out in a rubber sweat suit to lose weight, underhydrating himself, in murderous heat. Any thoughts, Dr. Pullen-em in?

  8. Despite my Eastern Medicine background (acupuncture, herbalist), we do receive about a quarter of our training in Western medicine, from M.D.’s, RN’s, Osteos, physical therapists, etc. I have no ax to grind here, but have been researching this NEW drug owing to a family member being prescribed THIS DAY, after a diagnosis of AFIB, two days ago, heart attack (not) scare. She is 88, and I must say, I will be back before 7am to speak with a Cardiologist, to discuss; If the concern is pooled blood in heart chamber, coagulating, stroke risk, why not TRIAL RUN aspirin first, monitor blood/INR test (there even exists a home test machine, COAG Micro, I believe, like glucose test), vs. Warfarin (33% of all elderly ER visits owing to use) or Pradaxa (maybe 2 years old, NO ANTIDOTE IF BLEEDING, FALL OR ACCIDENT, LIKE RN/TRAUMA NURSE WARNS, THIS IS TRUE), likely on market owing to $3k a year cost vs. $200 for old, flawed, but ANTIDOTE IF BLEEDING WARFARIN, which ppl also don’t like owing to more freq. blood tests needed)?? Also read med. study, believe 30k ppl, PRadaxa vs. Warfarin, Coumadin, Pradaxa increased risk of HEART ATTACKS by 33%. FACTS are, PHARMA pushes drugs on Doctors, who put them into patients…less is more, if ASPIRIN isn’t doing it (keeping blood thin enough), can THEN choose a blood thinner, no problem. Study said Pradaxa cut stroke risk in half, but twice as likely (I believe) than aspirin users to hemmorage, and no antidote means death! This was considered a wash/i.e. negligible to the point of no superiority for Pradaxa, in essence. AND DR. PULLEN, I AM OFFENDED YOU ANSWER THE LESS RISKY QUESTIONS, but COP OUT ON SERIOUS QUESTIONS, OR FAIL TO ADDRESS THEM (I am unable to address, you said, cpl times, in essence)…WHAT ABOUT THE TRAUMA NURSE COMMENT, OR MY OWN?

  9. My mother has been taking Pradaxa for a year.
    She is now having severe itching and is lightheaded.
    I am wondering if the dosage should be lowered.
    Thank you.

  10. Be very afraid of this drug. I would only take this as a last resort! Our chief trauma surgeon is forming data to submit to FDA for removal. The problem is that if you are in an accident where you are bleeding you are now in a life threatening position. THERE IS NO WAY TO STOP THE BLEEDING AND REVERSE THIS DRUG!!! You may very well bleed to death as doctors pour blood in you and it comes out everywhere else!! Be very careful. I can tell you that the surgeons will not operate on you if you come into the hospital on this drug. There have been hundreds of cases of trauma patients dying from this drug as we stand back and watch them die. This is a no brainer. Do not take this drug unless you have REALLY good reason. I would not let my family take this and as a nurse would caution the public.

  11. walter: To my understanding Pradaxa has FDA approval only for Non-valvular atrial fibrillation, although in any particular instance it is between you and your physician whether an off-label use of Pradaxa may be a better choice. DrP.

  12. I have a artificial Aortic valve and have just been changed to Pradaxa because I drink beer now and then. Can you tell me if Pradaxa is safe as an anti coagulant with my valve please.

  13. My father seems to be getting increased bloodpressure 220/90 and tingling in fingers after some months of being on pradaxa after been changed from warfarin. Can you comment?

  14. I have been taking a daily dose of warfarin, the drug of choice by my cardiologist, since Nov. 25, 2011, when I was hospitalized with an ischemic stroke. I would like to switch to Pradaxa but my Dr. said I should stay with the warfarin because there is no antidote for Pradaxa, as yet. He said that if I fall and hit my head, he can give me a shot to coagulate my blood if I should happen to bleed in the brain. With Pradaxa, he can give me nothing, no antidote.

  15. Often big drug companines will help if you ask. I’d contact the manufacturer. Also maybe your doctors assistant an ask for you. DrP.

  16. I need to take pradaxa but cannot afford too. Is there anyone who can help me. I am retired and I just barely making in now, I am alone and have to live on my ss only. It is very difficult for me to buy meds. Right now I have to stop fish oil and vitamins, Vit C that I was taking to take my other meds. I just don,t know what to do.

  17. For someone that has had RF ablation for Afib eight years ago but is currently in and out of Afib again would you recommend Pradaxa or an aspirin for a 72 year old male?

  18. I have been diagnosed with atrial fibrallation. My cardioligist prescribed Pradaxa.
    The VA will not fill my prescription as it is not in their formulary. Usually this has to do with cost, but reading your article leads me to believe Pradaxa is more cost effective than any alternative, especially considering the cost of a storke.
    Do you have any information on appealing the VA decision or getting them to add it to their formualry?
    Thanks.

  19. I have heard that there is a increase in heart atttachs with people takeing Pradaxa. Is this true?

  20. Kelly, No I’m not familiar with those side effects, but essentially any drug can have almost any side effect, so you need to discuss this again with your doctor. DrP.

  21. I noticed that I was coughing and my hands, wrists and ankles were swollen after I started Pradaxa. My cardiologist didn’t think that had anything to do with Pradaxa. I recently had to stop taking it for a minor dental procedure and during the time I wasn’t taking it, I wasn’t coughing and the swelling in my hands and feet went away. When I started taking it again, back they came. I haven’t seen anything anywhere about this side effect. I love Pradaxa, but don’t want to develop CHF from it! Have you heard anything about this type of reaction?

  22. Gil: I cannot give individual medial advice on this blog. Any medication can cause any side effect and your Dad needs to consult with his personal physician about this concern. In general the risk of stroke from a-fib is higher than the risk of bleeding from warfarin, but he needs to discuss his concerns with his doctor. Good luck. DrP.

  23. My father is 75 years old and was prescribed Pradaxa for AFIB in late September this year. He then complained that he was experiencing bothersome dreams, depression, and angry feelings. Have you heard about these side-effects before Doctor? His specialist wants him to start taking Warfarin but he’s very concerned about the risk of internal bleeding and might decline. Thank you for your help.

  24. Lin: I cannot give individual medical advice thru this forum but Torodol is in the NSAID family of medications which can cause gastric irritation and ulcers. In general we try not to have patients on the NSAIDs and anticoagulants. DrP.

  25. my docs just switch me to pradaxa. My co pay is 50.00 but have sign up for a savings coupon from pradaxa which will cut my cost to 30.00. It will make it ok

  26. I have just been changed from Warfran to Pradaxa. I had many extra nblood tests due to my unstable blood readings.

    One test would read 2.8 and the next one would bead 3.0 or 2.5. My diet was the same for each day. My doctor and I have not been able to locate the cause of such a variance.

    My co-pay was more than $86.00 and on a retirement; I may have to return to my previous RX.

    Jihadag

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