Abstract
Bleeding episodes in 5 hemophiliacs with antibody to F [factor] VIII were treated by activated F IX concentrate (FEIBA [F VIII inhibitor bypassing activity]). Relief of pain and hemostasis in affected muscles and joints were recorded in each case. One patient developed a mild attack of disseminated intravascular coagulation with an uneventful recovery. A substantial rise in natural inhibitors of coagulation was seen in 2 patients, and all but 1 experienced a rise in F VIII antibody titer.