Is It The End For INR?

Posted on by Mark

Treating patients with warfarin has always been a problem.  Even frequent regular INR testing fails to result in the majority of patients having clotting times within the recommended limits all the time.

Now, all that could become a thing of the past with the appearance of two new anti-coagulants which do not need clotting times to be checked regularly.  Dabigatran (Pradaxa) and Rivaroxaban (Xarelto) are the names of the drugs.

They have been around for a couple of years now with the main obstacle to their use being the price; dabigatran costs over £700 a year and rivaroxaban somewhat more.  This price becomes a little more sensible when balanced against a saving of over £300 a year on INR testing.

It becomes even more sensible when all patients taking the drug have their clotting times always within the recommended limits.

NICE has now recommended their use in people with atrial fibrillation over the age of 75; or 65 with either diabetes, coronary heart disease or hypertension.

People with one of these conditions plus atrial fibrillation are at high risk of stroke and, if they do not fall into one of these categories, should be taking low dose aspirin.

Apart from the cost, there is only one problem with these new drugs.  This is that they have, as yet, no antidote should bleeding occur.  However, patients with bleeding tendencies should not be taking them anyway; neither should patients taking these drugs be treated with any drug which can cause bleeding such as aspirin and NSAIDs.

So far, then, it seems all good news with these drugs and it is only a matter of time before they will become the gold standard of anticoagulant treatment.

But that’s not all. The story moves on even further with regard to the prevention of stroke in people with atrial fibrillation.  New guidelines from the European Society of Cardiology recommend that “aspirin should not be used for the prevention of stroke as it is ineffective”!

They also recommend that what they call Novel Oral Anti-Coagulants (that’s dabigatran and rivaroxaban to you and me) should be used rather than warfarin because, they go on to say, they offer comparable, if not better, efficacy, safety and convenience.

So, PCT’s or their equivalent will be treading on very unsafe ground if they refuse to allow GP’s to prescribe dabigatran or rivaroxaban purely on cost grounds.

The writer’s wife has just started taking dabigatran; whether that’s a recommendation or not is a moot point.

Find out more on our Cardiovascular Disease distance learning course and update day.