An illustrative case and a review on the dosing of recombinant factor VIIa in congenital factor XI deficiency

Summary.  Recombinant activated factor VII (rFVIIa) has been used in a very limited number of patients with severe factor XI (FXI) deficiency. The dose and duration of treatment has varied greatly between these case reports. In a few of these cases there was also evidence of thrombotic complications. We present here a report on one additional patient with congenital FXI deficiency. For two major orthopaedic procedures in this patient we used rFVIIa as a single bolus dose followed by continuous infusion at a low rate. The data from these treatment episodes, together with those from a review of the published cases, lend support to the concept of using much lower doses than in haemophilia with inhibitors. A bolus dose of 20  μ g kg −1 and thereafter maintenance of the FVII activity at approximately 3 IU mL −1 appears effective and safe.