Single-dose recombinant activated factor VII therapy in hemophilia patients with inhibitors.

Recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) is well established as an effective hemostatic agent for the management of hemorrhage in hemophilia patients with inhibitors. Its use in prophylaxis is currently being investigated. On-demand treatment schedules usually involve multiple bolus doses of 90 to 120 microg/kg administered every 2 to 3 hours, but recent evidence from randomized controlled trials suggests that the use of higher single doses is equally safe and effective when used for the home treatment of hemarthroses. Consequently, the use of a single dose of 270 microg/kg rFVIIa for the treatment of bleeds in inhibitor patients has recently been approved by the European Medicines Agency (EMEA). Such high-dose regimens may overcome the rapid clearance rate observed in pediatric patients, and may be more convenient for patients with poor venous access. It also has been suggested that individually tailored single-dose therapies might be beneficial in selected groups of patients, although proper monitoring of such patients is advised. Further research should contribute towards more effective dose optimization of rFVIIa in hemophilic inhibitor patients.