More on Pradaxa

I hope we are right.

Dabigatran (Pradaxa) use in my community has taken off. It’s not just AF-doctors, it’s all doctors, internists and cardiologists alike. Honestly, it’s a little scary.

That’s why I read with great interest anytime other practicing doctors speak about how they use the 4-month-old blood-thinner. Remember, this is not a just a new pill; it’s an entire paradigm shift.

Today, on Cardio-Exchange (an online community of cardiovascular professionals from the NEJM), Dr Samuel Goldhaber, Director of the Venous Thromboembolism Research Group and Medical Co-Director of the Anticoagulation Management Service at Brigham and Women’s Hospital, answered five practical questions about the use of dabigatran.

Here goes:

How should we use dabigatran around the time of cardioversion—a common procedure to terminate AF?

Dr Goldhaber confirmed the established practice that AF patients considered for cardioversion should have their blood thin for three weeks before, and 4 weeks after the shock.  That’s the same protocol that we use with warfarin. The reason we do this is to prevent blood clots that might have occurred in the fibrillating atria from dislodging after the shock restores regular atrial squeezing.

Does IV or subcutaneous blood thinners, like heparin or enoxaparin (Lovenox), have any role as a bridge to dabigatran in newly-discovered AF patients?

The answer is no. Unlike warfarin, which takes about three days to thin the blood, Dabigatran begins working in only 60 minutes. This is one of its greatest advantages: patients that require immediate blood-thinning no longer require a shot. Now we can simply have them swallow a pill. Thinning the blood without needles is HUGE!

How should we transition patents off their current blood thinners—usually warfarin—to dabigatran?

When patients stop taking warfarin, the blood begins to thicken in a day or two. Dabigatran thins the blood immediately. Put together, it made sense to me to start dabigatran 24-48 hours after the last warfarin dose. Dr Goldhaber said that’s how he does it as well. Good.

In the event of bleeding, is there an antidote for dabigatran?

No. Dabigatran does not have an antidote. That sounds bad, but the good news is that when dabigatran is stopped the blood thickens in a matter of hours. After four months of dabigatran use, I have yet to see, or hear of a bleed with dabigatran.

What should doctors do if a patient on dabigatran has repeated symptoms that suggest the presence of blood-clots–like stroke?

The absence of a test to measure dabigatran’s effect is one of its most relevant differences with warfarin. With warfarin, measuring the INR allows confirmation that the blood is thin—that the patient is taking the medicine. With dabigatran, the thinness of blood is unknowable.  That’s why when patients on dabigatran have a stroke, Dr Goldhaber suggests that we “take a careful history to determine whether one or more doses of dabigatran were omitted.” Only the patient knows whether they are taking the medicine. This personal responsibility thing is also a paradigm shift. One that I find very intriguing.

Thanks to Cardio-Exchange, and Dr Goldhaber for providing such practical information.

JMM

Comments

  1. says

    John – I am holding out hope that eventually I can move off of warfarin so I have been following your posts as well as others to see where dabigatran is heading. Keep up the blogging.

  2. Jim Arnett says

    Do any pharmcoeconomic studies exist that compare the total cost of appropriately monitored warfarin vs. dabigatran. With my overwhelmingly Medicare population, and the Part D “donut hole” warfarin may make more economic sense, as anticoagulant monitoring is typically a medical benefit and, thus, has no effect on true out of pocket costs for drug therapy as dabigatran or a LMWH will.

    • says

      Jim,

      Check out this Annals of Internal Medicine trial. It suggests, with some complex statistics, that dabigatran may be cost-effective in the US. Your point about (out of pocket) individual costs is well taken, as what a patient pays construes how they view how cost-effective a pill is.

  3. Ronald Hirsch, MD says

    The rush to use Pradaxa is misguided. Didn’t the liver failure deaths from Multaq teach cardiologists anything? Patients may be started on Pradaxa in the hospital but when they get to the pharmacy and are asked for $250 (no part D coverage or tier 3 status), they will walk out with nothing. I’ll let other doctor’s patients stroke out or die. Talk to me in 2 years and then I’ll decide if I am going to switch from $4 warfarin.

    • says

      Dr H,

      Your pessimism could be right.

      But I doubt it.

      In the 18,000-patient-strong RE-LY trial, of which 12,000 took dabigatran, there were no liver issues. Also, dabigatran has been used in Europe for two years without any evidence of liver toxicity.

      Your point about the high cost of dabigatran is well taken. It’s true, 250 dollars a month for a pill which doesn’t make a patient tingle with delight won’t fly. That said, I’m told that the drug has already been moved to second tier by more than a few payers. I’m also looking forward to the FDA approval of two other dabigatran competitors: apixaban and rivaroxaban. Hopefully, this will drive down prices.

  4. Latena says

    I’m still a little in shock that my doctor took me off Coumadin yesterday since I was expecting to be on it for the rest of my life (I’m only 60!). I haven’t changed my prescriptions yet since I’m doing my research. My concern, what are the issues with stomach problem with Pradaxa? I already have some problems and don’t want that to get worse. Are the stomach problems similar with Coumadin and Pradaxa?

  5. Dennis Brown says

    Is there anything that can be done to reduce the heartburn ?Another way to take the Pradaxa?Do people taking the lower dose get heartburn?

  6. Latena says

    This is my 4th day on Pradaxa. When I started on Pradaxa I got immediate severe heartburn when I took a pill. Now I take the pill with a ‘smoothie’ made of 1 cup almond milk and 1 scoop of whey protein powder and some berries. The heartburn has completely gone away. A different food item may work for others, but this is the answer for me!

  7. David says

    Dear John,
    I am a 45 year old man who is on Warfarin for a blood clot in my leg. I recently had pain in the same leg. When the tests were run they found new blood clots. They are not sure where the clots are coming from. They put me on Lovanox along with Warfarin. They told me that I was one of several people who have failed on Warfarin. Would this Pradaxa be better for me?

    Kind regards,
    David

    • says

      David,

      I do not know the answer to your question. But, I can say that dabigatran has been used in Europe for the treatment of blood clots in the legs. Though it makes sense that dabigatran is a better blood thinner than warfarin, at the current time it is only approved in the US for the prevention of stroke in AF.

  8. Dean says

    My cardiologist would like to start me on Pradaxa. I have no problem changing from Warfarin to Pradaxa, but I was told by his nurse that I would need to have a blood test every 3 months while I am using Pradaxa. Is there a new blood test that shows the blood thinning effectiveness of Pradaxa?

    Thank You,
    Dean

    • says

      No. I am not sure what your doctor is checking.

      Keep in mind that dabigatran gets cleared from the body by the kidneys. When kidney function is significantly impaired (GFR <30) reducing the dose of dabigatran to 75mg twice daily is recommended. (Patients whose GFR is less than 15 should not take dabigatran.) In this way, dabigatran is not unlike other drugs that are cleared through the kidneys, and thus should be “adjusted” in patients with reduced kidney function.

      Perhaps this would be a good question for your doctor.

  9. says

    The manufacturer of Pradaxa has recommendations for discontinuation of the medication prior to surgery that are dependent upon the patient’s creatinine clearance. Usually this lab result is not available to the surgeon to make recommendations until a day or two before the surgery date. Recommended discontinuation days are from 1-5 days, with a statement to consider longer times for patients undergoing major surgery. What are cardiologists suggesting?

  10. Latena says

    I see people on the various Pradaxa blogs stating that they are taking Nexium and antacids to relieve the gastrointestional problems caused by Pradaxa but the information I received is that antacids can interfere with the effectiveness of Pradaxa. What is the truth? What about taking one of the probiotic supplements that are so popular these days?