VOLUME

The fact that many doctors still refuse to replace the anticoagulant warfarin with dabigatran, despite dabigatran’s better safetyprofile, is not a scientific problem but a psychological one. In my view there are four fears in doctors’ minds:

1) Fear of dabigatran’s hidden higher incidence of bleeding.

2) Fear of bleeding crisis when dabigatran’s antidote is not available.

3) Fear of overdose in Thai population when extrapolating the dose from Caucasian population.

4) Fear of higher cost for patients.

I address these four fears one by one below.

Fear of dabigatran’s hidden higher incidence of bleeding, is a fear based on news rather than evidence, particularly thehigh number of law suits reported on the internet. Some lawyers have launched websites offering their services to lodge suitsagainst dabigatran without any of the usual upfront payments. The FDA itself used to issue warning letters to say that it has beenworking on post marketing reports of dabigatran in view of the detection of hidden bleeding incidence not identified inpremarketing research. Some governmental health agencies in countries such as Australia and Japan have also issued warningson the uncertainty of the bleeding incidence rates of dabigatran. But news is only news and for the most part anecdotal. Therehas not been, to date, any reliable evidence showing that dabigatran carries a higher incidence of bleeding than warfarin does.On the contrary, the evidence shows that dabigatran carries lower overall bleeding incidence. Data from RE-LY study which isthe biggest study of its kind indicates that dabigatran has lower bleeding incidence than warfarin. Clinical practice guidelinessuch as the European Society of Cardiology (ESC) advise the use of dabigatran as a treatment of first choice for prevention ofstroke in AF since 2012. So rest assured, news goes off in one direction but the evidence goes in another.

Fear of a bleeding crisis without there being an antidote should be alleviated because there is an antidote to dabigatran now.A study using the dabigatran antidote called Idarucizumab was recently published in the New England Journal of Medicine. Itis a cohort study of 503 dabigatran users, of whom 301 users belong to the bleeding complication group and 202 users belongto preparation for operation group. The antidote idarucizumab, 5 grams dose was injected intravenously then the coagulogramswere follow within 4 hours. The study shows that idarucizumab can reverse the anticoagulation effect of dabigatran by 100%.The peak reversal time is 2.5 hours for the bleeding complication group and 1.6 hours for preparation for operation group.

Fear of Caucasian dose in Asian patients should be allayed given the study done in Japan. In that study researchers comparedthe dose of 150 mg vs 110 mg in Japanese patients and found that the dose of 150 mg can achieve better stroke prevention thanthe dose of 110 mg.

Fear of the cost of treatment, should be resolved by presenting the medication as an option to the patient. The patient should
be the one to decide whether he/she will pay more or not.

In summary, up until today evidence supports replacing warfarin with dabigatran in view of the better outcomes and safety
profile. Fear no more, doctor!