ISMP calls for FDA action on dabigatran bleeding risk

The high risk of bleeding in patients taking the anticoagulant dabigatran (Pradaxa) has been a major problem that the manufacturer and health experts have been trying to find solutions for over the last four years. Sixteen percent of patients experienced a bleed in one year, including 3.3% who had bleeds that required emergency medical treatment, according to one clinical trial.

Two new studies provide solutions to the high hemorrhage risk, according to the Institute for Safe Medication Practices (ISMP). The two studies, published in the Journal of American Cardiology in 2013 and 2014 found that a one-dose-fits-all approach raises the risk of major bleeding in many patients without an improving efficacy in stroke prevention, according to ISMP.

One of the studies found that a lower dose of 110 mg BID had a reduced bleeding risk but similar efficacy in preventing strokes compared with the single approved dose of 150 mg BID. Unfortunately, the FDA rejected the lower dose when it approved dabigatran in 2010.

However, the lower dose is available in Canada, Europe, Japan, Australia, and New Zealand, according to ISMP.

Another tool that would help reduce bleeding risk from dabigatran – a new lab test that identifies patients at highest risk for serious bleeding – is not available in the United States, according to ISMP. The Hemoclot Thrombin Inhibitor assay, manufactured by Hyphen Biomed, is available in Europe, Australia, and Canada, but is only available for research purposes in the United States, ISMP said.

“This test now has greater value because it can identify the 10% of patients with extremely high blood levels, even outside the five-fold variation range,” ISMP wrote in the February 2014 issue of ISMP Medication Safety Alert! Community/ Ambulatory Care Edition.

“FDA should strongly consider this important additional information about dabigatran, reassess the one-dose-fits-all recommendation, and reevaluate the Hemoclot Thrombin Inhibitor assay to reduce the risk of serious injury from one of the highest risk outpatient drug treatments,” ISMP wrote.