Tuesday, October 11, 2011


On the 5th October 2011, the Australian equivalent of US FDA, called the Therapeutic Goods Administration, issued a safety advisory on the use of Dabigatran.
Dabigatran is a anti-thrombin, factor 10 inhibitor, shown in the be effective in the prevention of ischemic strokes in patients with non-valvular atrial fibrillation. It was initially shown to be effective in the prevention of DVT in patients following hip replacement surgery. Many of us remember it as an expensive warfarin equivalent without the need for PT-INR monitoring. This has both good and bad consequences. It is good that there is no need to prick you every 3 months to check on your warfarin effects, ( as warfarin is a very fussy drug affected by many other drugs and foods ). However, if there is no way of effectively monitoring dabigatran, then when things go awry ( like things sometimes do ), there is no way to know.
The Australian warning came after they notice a significant increase in the number of bleeding following the increase use of Dabigatran. In 2009, Dabigatran was indicated ( in Australia ) for the prevention of DVT following lower limb surgery. The number of bleeders then were few. In April this year, Dabigatran was release for the indication of prevention of ischemic strokes in patients with non-valvular atrial fibrillation. Since that release, the number of bleeds following dabigatran use has increased. Now, the risk of bleeding with Dabigatran is about 16.6% in those taking the 150mg BD dose, and 14.7% in those taking the 110mg BD dose. This is against a risk of 18.4 % in those taking warfarin at therapeutic doses.
Should bleeding occur with the use of Dabigatran, it is usually gastro-intestinal, as oppose to warfarin, where bleeding may be largely intracranial.
It is important to note that such safety advisory has also been issued in japan and also New Zealand recently, for the same concern about bleeding.
Looks like cost is not the only downside to the use of Dabigatran. Bleeding is also a issue. It is good to note that all the three countries mentioned are Asian Pacific countries, where diet, and size may be more like us.
I think that physicians and patients should take note of the safety advisory, and use Dabigatran wisely, when proper indication.
Should bleeding occur, PT-INR is not helpful, and one may have to monitor the effects of Dabigatran crudely using aPTT and Thrombin Time, or even very crudely, the whole blood clotting time.
So this new kid has issues.

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