Use of Recombinant Factor VIIa Utilization Among a Hospitalized Pediatric Population

Recombinant activated factor VII (rFVIIa; NovoSeven® RT, Novo Nordisk, Bagsvaerd, Denmark) is a synthetic pro-coagulation factor derived from hamster kidney cells. The purpose of this study was to evaluate the prescribing patterns of recombinant factor VIIa (rFVIIa) at a single, tertiary care pediatric hospital by indication of usage and dose administered. Retrospective data was queried from the centralized pharmacy medication computer system. All patients receiving rFVIIa between September 2009 and September 2012 were included in the analysis. Over the three year period 887 doses of rFVIIa were administered to 186 patients. Only 4% of patients received rFVIIa for an FDA approved indication. The most common indication for off-label usage was refactory bleeding either during or following cardiothoracic surgery, accounting for 83% of all doses administered off-label. Despite being only a small portion of all patients receiving rFVIIa, the group receiving rFVIIa for an FDA approved indication received the majority of doses dispensed (72.6% of all doses). A significant difference (P < 0.0001) was noted in the dose administered to patients in the on-label versus off-label groups. Patients in the on-label group received a median dose of 113.6 mcg/kg (IQR 54.5 mcg/kg - 172.7 mcg/kg) versus a median dose of 74.4 mcg/kg (IQR 20.0 mcg/kg - 128.8 mcg/kg) in the off-label group. Prospective pediatric studies are needed to evaluate rFVIIa efficacy and safety in populations receiving the medication for off-label indications given increasing concerns involving the potential adverse effect profile of the medication as well as to develop evidence based dosing parameters for these indications.