Tag Archives: coumadin

THE COUMADIN ERA IS COMING TO AN END

admit oneCoumadin has had a virtual monopoly as an oral anticoagulant since it was first used in 1940 at Wisconsin General Hospital.   Discovered accidentally when scientists investigated hemorrhaging of livestock who ate spoiled sweet clover when grazing, it took a decade to isolate dicoumarol and use it in the clinic.

Initially showing success in preventing blood clots in heart attack patients who were recuperating with prolonged bed-rest, it was used in a multiplicity of settings to reduce blood clots and today is most widely used today for stroke prevention in the arrhythmia atrial fibrillation.  This monopoly is about to end.

The NOAC group of medication (NOvel AntiCoagulants) are about to displaced Coumadin use due to their ease of use, equivalency, and possible superiority.  Pradaxa, Xarelto, & Eliquis are the three major brands of these NOAC medications, and every month there is another publication in the scientific medical literature touting their use and benefits.

In atrial fibrillation, the NOACS are equal to, if not superior to Coumadin for prevention of stroke.  Their side effect profiles appear similar or better than Coumadin and they do not require special blood testing, the vaunted PROTIME, to monitor effects.

Beyond fibrillation, Xarelto has been approved for treating blood clots in the legs and lungs, and Eliquis appears that it will be approved soon (Pradaxa is not approved for this condition).   Additional indications are being investigated, including use in Mechanical Heart Valves, but that data remains uncertain and will await final proof of effectiveness before it displaces Coumadin as the drug of choice.

There are four hold-ups in the transition from Coumadin to NOACs and they are:

1.  Delineation of specific and definitive indications conditions that can benefit from NOACS (Atrial Fibrillation and Blood Clots are proven; Mechanical Hearat Valves and Heart Clots are unproven at this time)

2.  Lack of antidote to treat overdose.  Although this would seem to be a big ‘hold up’ the clinical evidence suggests that stopping/holding the NOAC medication in most instances results in acceptable clinical outcomes in patients with bleeding issues or trauma, and in exceptional cases that require it, there are some novel IV substances that may help reverse their blood-thinning properties.

3.  Cost….as the medications are approximately $10 per pill (cash), while Coumadin is only pennies

4.  Lack of extensive data to match Coumadin.  As Coumadin has been around for 70+ years, it is difficult for these newer agents to match the data and clinical experience physicians have with these medications, but well-designed studies are being done on tens-of-thousands of patients to attempt to get data that is statistically strong and very reassuring.

So, patients with fibrillation that have varying Protimes (blood test results) or those who have difficulty getting their blood tested, will want to strongly consider the NOAC medications and it appears that without some profoundly negative studies on these medications, they are poised to end the era dominated by Coumadin.

NEW COUMADIN ALTERNATIVES….RANGE OF USE STILL TO BE IDENTIFIED

dreamstime_l_13704313Xarelto and Pradaxa and two new anti-coagulant medications that have similar effects to Coumadin (warfarin).    Because their mechanism of action is different than Coumadin, they are simpler to use as they do not require blood monitoring.

Pradaxa was approved over two years ago and appears to be equally effective to Coumadin for atrial fibrillation, but at the present time, it is not useful in other settings such as blood clots and heart valves.   More information will be forthcoming on additional uses, but for now it is limited to atrial fibrillation

Xarelto, on the other hand, has shown effectiveness in blood clot treatment and is approved for the acute treatment of deep venous thrombosis of the leg and pulmonary embolus.  This will be a great boon to those who need it.   Due to its effectiveness in this setting, it has been presumed that Xarelto will be useful for treatment in mechanical heart valves as these valves always require anticoagulation.  But the latest study shows that Xarelto is not effective in this setting and cannot be considered equivalent to Coumadin.

 

http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm332949.htm

 

 

ALTERNATIVES TO COUMADIN GAINING MOMENTUM

A recent analysis of the new anticoagulants to replace Coumadin (Warfarin) is looking quite favorable when treating blood clots.  This is expanding their indication, usage and safety.

In the U.S. the two alternatives are PRADAXA and XARELTO, with Xarelto  appearing to be somewhat more advantageous with less issues from bleeding.

Such alternatives are sorely needed and provide a great deal of benefit as regards convenience as they do not require blood monitoring.

On the other hand, there is no ready ‘antidote’ to these new anticoagulants, and until more experience accumulates as to their safety in various populations, we will remains slow to adopt their usage across the board.

Read more if you are interested:
http://www.bmj.com/content/345/bmj.e7498