Australia’s Therapeutic Goods Administration approved dabigatran (Pradaxa, Boehringer Ingelheim Pharmaceuticals) in April for the indications to prevent stroke and other blood clots in atrial fibrillation patients; however, on Oct. 5, the department put out a safety advisory due to an increased risk of bleeding linked to the drug.
The number of bleeding-related adverse event reports has increased, with 124 serious events reported to TGA since 2009. Previous clinical trials have shown that the risk of bleeding per year of treatment with dabigatran was 16.6 percent in those administered the 150 mg twice daily dose and 14.7 percent in those administered the 110 mg twice daily dose. In comparison, the rate of bleeding events for patients administered warfarin was 18.4 percent.
After investigation, TGA is now warning clinicians to give careful consideration to the suitability of their patients for dabigatran. If an emergency situation should occur, TGA recommended that clinicians perform a thrombin time test or an activated partial thromboplastin time test. However, TGA said that prothrombin time (INR) should not be used.
The FDA approved 150 mg and 75 mg doses of dabigatran in October 2010, making dabigatran the first alternative to warfarin in the U.S.