Why is Pradaxa's INR range (2.0-2.5) not acceptable for mechanical valves?

[Gary Miller]

I read the that the INR range for the new ACT drugs is 1.5 -2.0 or 2.0-2.5. Why are the mechanical valves so different if the INR's are in the same range?

 

[pellicle]

Well firstly Pradaxa has no INR, meaning you are not able to measure its anticoagulant effect. Then there is the issue that it has not passed safety tests.

THURSDAY, Sept. 26, 2013 (HealthDay News) -- When used by patients with mechanical heart valves, the blood thinner Pradaxa raises the risk of both dangerous clots and bleeding around the heart, a new study says.
The bottom line for lead researcher Dr. Frans Van de Werf, chairman of the department of cardiovascular medicine at the University Hospitals Leuven in Belgium, is "don't use Pradaxa in patients with a mechanical valve."
In fact, the trial was halted early and the U.S. Food and Drug Administration subsequently issued a warning that said this particular group of heart patients should not take Pradaxa because of an increased chance of a stroke or heart attack.
Pradaxa (dabigatran) is a drug that prevents clotting. It has been approved as an alternative to warfarin for patients with an abnormal heartbeat called atrial fibrillation, the researchers noted.

Then there is stuff like this

http://mobile.abc.net.au/news/2014-0...thheld/5642436

Figures obtained by the ABC reveal Pradaxa has been associated with 280 deaths in Australia and 1,400 adverse drug reactions in the past five years, including abdominal bleeding, brain haemorrhages, strokes and heart attacks.

Given how many are on warfarin and how few are on pradaxa that's horrifying.

Its anticoagulant effect is not readily reversible either, unhelpful in the ER.

If you have a Dr encouraging you onto pradaxa make an excuse and get out fast.