Dabigatran: life-threatening bleeding

Dabigatran is an oral anticoagulant that inhibits thrombin but not vitamin K. In mid-2012, there was no commercial test to monitor its anticoagulant effect, nor an antidote. In mid-November 2011, the European pharmacovigilance database contained 256 reports of haemorrhagic deaths attributed to dabigatran. Nearly 800 cases of severe haemorrhage have been reported in Australia, Canada, Japan, New Zealand and the United States. A randomised trial comparing dabigatran with warfarin, and 5 studies of several hundred serious bleeding events, identified factors that increased the risk of bleeding. They included even mild renal failure, age over 75 years, body weight less than 60 kg, switching between anticoagulants, opening the dabigatran capsules before ingestion, and concomitant use of drugs that interact with dabigatran. A dabigatran dose below 220 mg per day does not protect patients from the risk of haemorrhage. In practice, dabigatran should be reserved for patients with a high risk of thrombosis in whom the target INR cannot be maintained on antivitamin K therapy alone. The risk of bleeding must be taken into account, renal function must be closely monitored, and patients and their carers must be correctly informed about this risk.