Recombinant activated clotting factor VII (rFVIIa) in the treatment of surgical and spontaneous bleeding episodes in hemophilic patients

Heng Joo Ng, Lai Heng LeeDepartment of Haematology, Singapore General Hospital, SingaporeAbstract: Inhibitors against replacement clotting factors occur in approximately 30%–40% of patients with hemophilia A and 1.5%–3% of patients with hemophilia B. In this group of patients, bleeding events are best treated with bypassing agents. Recombinant activated factor VII (rFVIIa) has become the first-line agent in treating surgical and non-surgical bleeding in many centres with efficacy at standard 90 µg/kg doses approaching 90%. The greater efficacy is associated with early initiation of treatment, as well as, possibly larger doses of rFVIIa. A higher concentration appears to be essential in initiating an adequate thrombin burst, which results in a stable clot. Higher dosage regimens, home therapy and continuous infusion regimens are continuously evolving as we strive to define optimal dosing strategies in hemophilia patients. rFVIIa has been a remarkably safe agent for hemophiliacs but with high dosages being advocated and older patients being given such doses outside a trial setting, thromboembolic events remain a concern. Keywords: recombinant activated factor VII, hemophilia, inhibitors, bleeding.