Recombinant activated clotting factor VII (rFVIIa) in the treatment of surgical and spontaneous bleeding episodes in hemophilic patients.
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 microg/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.
Ng
Heng Joo
HJ
Department of Haematology, Singapore General Hospital, Singapore. ng.heng.joo@sgh.com.sg
Lee
Lai Heng
LH
D001777:Blood Coagulation / Q000187:drug effects; D003029:Coagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005167:Factor VII / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use*; D015942:Factor VIIa; D006467:Hemophilia A / Q000150:complications*; D006470:Hemorrhage / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use; D013514:Surgical Procedures, Operative / Q000009:adverse effects*; D013923:Thromboembolism / Q000139:chemically induced; D013927:Thrombosis / Q000139:chemically induced; D016896:Treatment Outcome
D003029:Coagulants; D011994:Recombinant Proteins; D005167:Factor VII; C103587:recombinant FVIIa; D015942:Factor VIIa