Treatment with recombinant activated factor VII in a patient with hemophilia A and an inhibitor: advantages of administration by continuous infusion over bolus intermittent injections

Recent studies have shown that treatment with a continuous infusion of reco mbinant activated factor VII (rFVIIa) is far more convenient than administr ation by bolus intermittent injections and may allow a substantial reductio n in the dose. We present the case of a 26-year-old patient with hemophilia A, who had a high-titer inhibitor to both human and porcine factor VIII, a nd who had recently been admitted to hospital because of a bilateral severe ilio-psoas hematoma. Two subsequent courses of treatment with rFVIIa by bo lus intermittent injection showed only a partial efficacy. A further admini stration of rFVIIa was therefore carried out using a continuous infusion re gimen that proved to be fully efficacious. During the continuous infusion c ourse levers of factor VII coagulant activity were in the range 18.2-5.2 U/ ml while the prothrombin time, expressed as an International Normalized Rat io, remained within the range 0.57-0.71. The continuous infusion, compared with the administration of the bolus intermittent infusion, reduced the amo unt of rFVIIa required by approximately 40-50%. Statistical analysis demons trated that there was a strong positive correlation between the rate of inf usion of rFVIIa and levels of factor VII coagulant activity (r = +0.941; P < 0.001), and a very significant negative correlation between levels of fac tor VII coagulant activity and prothrombin time values (r = -0.897; P < 0.0 01). In accordance with previous findings, our experience confirms that, wh en prolonged therapy is required, treatment with rFVIIa by continuous infus ion is more convenient than administration of bolus intermittent injections , and may allow the saving of a large amount of drug. Moreover, we suggest potential additional advantages of the continuous infusion regimen over bol us intermittent injections, such as a better efficacy and a stronger correl ation between prothrombin time and factor VII coagulant activity levels. (C ) 1999 Lippincott Williams & Wilkins.