Regulators in Europe have again asked Boehringer Ingelheim, the manufacturer of the blood thinner Pradaxa, to update the drug’s label with additional information regarding Pradaxa bleeding side effects. According to the European Medicines Agency (EMA), the new guidance should include more specific information on when Pradaxa must not be used, as well as advice on managing patients and reversing the anticoagulant effect if Pradaxa bleeding occurs.
Pradaxa was approved in Europe in March 2008 for the prevention of venous thromboembolic events following hip or knee replacement surgery. The blood thinner recently had its European approval expanded to cover patients with non-valvular atrial fibrillation to prevent stroke and systemic embolism. According to a report from Pharma Times, the number of fatal bleeding events among Pradaxa users spiked following that expansion.
The EMA’s Committee for Medicinal Products for Human Use (CHMP) had concluded an earlier review of Pradaxa in November 2011, after it had been linked to 250 patient deaths. At the time, CHMP asked that label information on bleeding risks be strengthened. The Committee also advised caution when using Pradaxa, and said it should be prescribed at lower doses to older patients and those with kidney problems.
On Friday, CHMP pointed out that the occurrence of fatal bleedings with Pradaxa seen in post-marketing data “was significantly lower than what was observed in the clinical trials that supported the authorization of the medicine,” but said the issue “should nonetheless be kept under close surveillance”.
Pradaxa was the first of a new class of blood thinners called direct thrombin inhibitors. Pradaxa has been marketed as a safer alternative to decades-old Coumadin (warfarin). Among other things, Coumadin can cause dangerous interactions with other drugs. Patients taking Coumadin also have to avoid foods that are high in vitamin K, like leafy greens, liver, green tea and cauliflower. Patients’ blood must also be regularly monitored to ensure it is working well.
Like all blood thinners, Pradaxa and Coumadin can cause serious internal bleeding. But there are antidotes for Coumadin bleeding, including the administration of vitamin K. However, there are no readily available antidotes for Pradaxa bleeding side effects. In fact, there have been cases reported recently where Pradaxa patients died from serious internal bleeding after minor trauma, such as a fall in which they hit their head.
Last December, the U.S. Food & Drug Administration (FDA) launched a review of Pradaxa over reports of bleeding-related side effects. Regulators for Japan have also directed Boehringer Ingelheim to strengthen warnings for the Pradaxa
In April, the Institute for Safe Medicine Practices (ISMP) reported that Pradaxa was associated with a total 856 reports of serious, disabling or fatal injury, including 117 bleeding deaths, in the second quarter of 2011. In its previous QuarterWatch report, the ISMP had found that more than 500 cases of serious Pradaxa bleeding had been reported to the FDA in the first quarter of 2011.