[Continuous infusion of coagulant factor concentrates and its pharmacokinetics in patients with hemophilics having low titer inhibitor].

To treat acute episodes of bleeding in patients with hemophilia and low titer inhibitor, "neutralization", which is the neutralization of inhibitors using high dose coagulant factor infusions, is often selected. However, it is difficult to anticipate the dose of continuous infusion (CI) of coagulation products after neutralization. We herein present the CI of coagulant products in 2 patients with hemophilia and low titer inhibitors and discuss the pharmacokinetics of coagulation products. Both patients have had good responses regarding hemostasis using CI after the neutralization. The volume of distribution of coagulation products in case 2 is 3.7 times and clearances of coagulation products are from 2 to 3 times as high as those in patients without inhibitors. It is suspected that the clearances in patients with an inhibitor are higher than those in patients without an inhibitor because a large amount of inhibitor is involved in the extra-vascular space such as tissue fluid and the reticuloendothelial system. The dose for CI of coagulation products after neutralization in patients with inhibitor might be better clarified if the reported cases increase and the pharmacokinetics are more deeply analyzed.