Recombinant factor VIIa: its background, development and clinical use. 
To examine the development of recombinant FVIIa (rFVIIa); a new concept of inducing hemostasis.  It was developed for use in hemophilia patients with inhibitors against FVIII or FIX with the vision to provide these patients with a therapeutical option to be used instead of FVIII or FIX.  For the first time it was shown that pharmacological doses of FVIIa induced hemostasis.  Hemostasis was achieved by rFVIIa in major surgery (repeated doses) as well as in a home-treatment setting (one single injection) in severe hemophilia patients with inhibitors.  A recent study indicates that rFVIIa may be useful as prophylaxis.  In heavily bleeding nonhemophilia patients rFVIIa was shown to induce hemostasis.  Pharmacological doses of rFVIIa enhance thrombin generation on activated platelets resulting in the formation of tight hemostatic fibrin plugs resistant against premature proteolysis.  High doses of rFVIIa seem to be safe probably due to its localized effect.  Pharmacological doses of rFVIIa induce hemostasis in severe hemophilia and in nonhemophilia patients with profuse, heavy bleeding.  rFVIIa enhances thrombin generation on activated platelets, thereby initiating the formation of strong, tight fibrin hemostatic plugs resistant to premature lysis.  It also seems to be safe in high doses.