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

Abstract

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.