Novel Oral Anticoagulant Therapies

By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.

So many HeartMD site visitors have asked me lately about the “new generation” of blood thinners – novel oral anticoagulant therapies; in particular, about Xarelto and its side effects. Maybe it’s because of more aggressive advertising…who hasn’t seen TV commercials featuring celebrities and professional athletes discussing their blood thinning drugs over a game of golf? Maybe doctors are prescribing blood thinners more readily these days, and perhaps this is due to more patients asking their doctors about Xarelto or other novel oral anticoagulants they’ve seen advertised on TV. At the end of the day, blood thinners are a hot potato, but people want answers…

While I’ve written about more established blood thinners and oral anticoagulants like Coumadin based on experiences with my patients, I’ve not been in active practice for a while, and am less familiar with the newer novel anticoagulants like Eliquis, Xarelto, Pradaxa and Savaysa (some of which may be viable and more preferable alternatives to Coumadin).  So I asked my physician, friend and esteemed colleague, Dr. Richard Delany – an integrative cardiologist who is also board-certified in internal medicine, and critical care – to share his thoughts about these new oral anticoagulants. Here’s what he has to say…

New Blood Thinners: Novel Oral Anticoagulants (NOACs)

By Richard Delany, MD, FACC 

Atrial fibrillation, a specific heart rhythm irregularity, is one of the most common reasons doctors prescribe blood thinners for long-term use. Typically, a patient is placed on long term warfarin (Coumadin) medication in order to diminish the body’s ability to form clots. The purpose of such oral anticoagulant use is to reduce the chances of having a stroke.

Since 2010, four “Novel Oral Anticoagulants (NOACs)” have been approved by the Food and Drug Administration. They represent new types of drugs that can safely replace warfarin (Coumadin) in patients with a non-valvular type of atrial fibrillation. I stress “non-valvular” because these new blood thinning drugs are not safe replacements for Warfarin (Coumadin) in patients who have an underlying prosthetic heart valve.

The 4 new drugs are: (1) apixaban ( Eliquis), (2) rivaroxaban (Xarelto), (3) dabigatran  ( Pradaxa), and (4) edoxaban ( Savaysa).

How NOAC Anticoagulants Work

Like Coumadin, these novel oral anticoagulant meds work by interfering with the body’s normal clotting factors, but they do so in different ways than does Coumadin. Coumadin blocks Vitamin K-dependent clotting factors. Dabigatan (Pradaxa) acts as a direct inhibitor of thrombin, a specific protein of the normal clotting process. The other 3 available NOACs  – Apixaban (Eliquis), Rivaroxaban (Xarelto), and Adoxaban (Savaysa) –  work by inhibiting Factor Xa, yet another of the body’s clotting factors.

New Anticoagulants: Good Alternatives to Coumadin?

Using the current estimate of achieving a successful Coumadin control rate of 69%, a number of medical trials have shown that NOACs are as good as, and actually more effective than, Coumadin for reducing risk of stroke. Even though this 69% estimation of Coumadin control may be too low, the novel anticoagulants are good alternatives for many patients who have non-valvular atrial fibrillation. New patients needing chronic anticoagulation will likely receive a NOAC anticoagulant first over warfarin. On the other hand, patients who have been on long term warfarin, and are doing well – that is, without complications or difficulty with the monthly (or more frequent) testing or other concerns – should probably not be routinely changed to a new blood thinner like Xarelto, Pradaxa or Eliquis.

Things to Know About NOAC Anticoagulants

Here are some other important things to know about the new anticoagulant drugs:

  • NOACs do not require that you get monthly (or even more frequent) blood tests to make sure the medication is safe and working properly.
  • NOACs have all been shown to be as good as, and often tended to be better than, warfarin at preventing stroke.
  • Unlike Coumadin, NOACs leave your body quickly. As a result, if you’re on a NOAC, you need to be compliant and be careful not to miss a dose (as the anticoagulation effect will diminish more quickly than it would if a dose of Coumadin were missed).
  • If your blood becomes too thin and results in bleeding complications, there is no readily available antidote regimen – short of stopping the drug – as there is with warfarin. To quickly reverse the anticoagulant effects of warfarin, you can be given a Vitamin K injection and intravenous fresh frozen plasma. Whereas, with an NOAC, the only option is to stop taking it, and wait for the anticoagulation effect to diminish over a 1 to 2-day period.
  • If you’re going to have surgery, you’ll generally need to stop taking a NOAC drug 1-2 days both before and after the surgery. While this is the most common recommendation, care will be personalized to suit your particular set of needs. If you have moderate kidney disease, for example, you may need to stop taking a NOAC drug for a longer period of time before and after surgery.
  • ALWAYS tell your doctor about other medicines or nutritional supplements you are taking, as they can interact with blood thinning meds.

Which Novel Oral Anticoagulant Therapy Is Best for You?

When recommending medication, physicians consider all the available information, including safety, proven effectiveness, timing of the dosing, your medical history and current medical condition, drug interactions and the cost to you – the patient. The physician’s choice of medication, then, depends on your situation and needs, and should be trusted as the right choice. I hope the information below – based on my research and experience with these drugs – is useful to you, when discussing blood thinning medications with your doctor.

Apixaban (Eliquis)

Eliquis is my favorite of the four new blood thinners because it is the easiest and safest to use, as long as 2 daily doses are acceptable. Overall, apixaban is well tolerated, and lowers the risk of stroke very safely with a low incidence of bleeding into the head. It has the lowest incidence of all NOACs in bleeding from other bodily sites (stomach, intestines, bladder). Generally, patients should take 5 mg twice a day, and patients with kidney disease should take 2.5 mg twice a day.

Rivaraban (Xarelto) and edoxaban (Savasya)

For me, Xarelto and Savasya are tied for second place. Both drugs are taken once a day (15 to 20 mg Xarelto or 30 to 60 mg Savasya); less if you have kidney disease. Higher doses reduce the risk of stroke, but the lower doses are not as good as warfarin in reducing stroke. Common Savaysa and Xarelto side effects include easy bruising and bleeding (nosebleeds, for example).

Recently, though, Xarelto has been under fire: as reported in the NY Times, patients are suing Johnson & Johnson and Bayer, claiming lack of safety due to an omission of critical information (specifically, lab data) in a letter published in the New England Journal of Medicine, upon which doctors have relied when prescribing the medication. Hence, depending on how this lawsuit pans out, it’s possible that faith in Xarelto may drop significantly.

Dabigatran (Pradaxa)

Xarelto scandal aside, Pradaxa is my least favorite NOAC anticoagulant. 150 mg are generally given twice a day (75 mg twice a day if you have kidney disease). While bleeding rates are lower in the head, they are higher in the stomach and intestines. Stomach pain is a commonly reported Pradaxa side effect. Patients who already have heartburn and/or stomach pains should avoid dabigatran.

© 2016 HeartMD Institute and Dr. Richard Delany. All rights reserved.

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