 Currently, there are no laboratory assays that can assess the pharmaceutical activity of the available agents known collectively as bypassing agents, which negatively impacts the treating physicians ability to manage these patients, leaving decisions on the dosing regimen to trial and error. Both agents, FEIBA and recombinant activated factor VII rFVIIa, are approved for the treatment of bleeding in inhibitor patients with recommended dosing regimens that are based on clinical trials. However, a significant amount of experimenting with other dosing regimens is used by physicians and patients. 