We have prospectively monitored treatment of
haemophilia patients with inhibitors by
recombinant factor VIIa (
rFVIIa) administered by continuous infusion to obtain more insight in the underlying factors of the clinical efficacy of this administration method. At present, 43 treatment episodes of 14 different Dutch
haemophilia inhibitor patients are included in the database. Analysis of the data showed a discrepancy between the efficacy of
rFVIIa continuous infusion treatment of acute and surgical bleeds in the oral cavity [one (14%) effective, two (29%) partially effective, four (57%) not effective] and other parts of the body [29 (80%) effective, four (11%) partially effective, two (6%) not effective, one (3%) impossible to classify]. Patients who had acute or surgical oral cavity bleeds, uncontrolled by
rFVIIa continuous infusion, reacted favourably to
rFVIIa continuous infusion in other locations of the body. Acute
bleeding episodes in the oral cavity, which could not be controlled by
rFVIIa continuous infusion, stopped when the treatment regimen was switched to
rFVIIa bolus
injections. Finally, haemostatic control during dental extractions was excellent after the initial
rFVIIa bolus injection preceding the continuous infusion, but rebleeds occurred in all patients within 48 h under
rFVIIa continuous infusion coverage. These observations suggest that the efficacy of
rFVIIa continuous infusion depends, at least in part, on the location of the body in which the
bleeding occurs and that
rFVIIa bolus
injections are more effective than
rFVIIa continuous infusion in the oral cavity. We hypothesize that the inability of
rFVIIa continuous infusion treatment to sufficiently inhibit fibrinolysis is the underlying cause of the decreased efficacy of
rFVIIa continuous infusion treatment in the oral cavity.