Clinico-pharmacological studies with recombinant hirudin

The pharmacokinetics of recombinant hirudin were studied in 9 healthy subjects after single intravenous, subcutaneous or intramuscular doses of 0.1 mg/kg. Generally, administration of r-hirudin was tolerated without side effects. An assay was used which detects the inhibitor in blood and urine by its antithrombin activity. Absorption, distribution and elimination of r-hirudin were found to be corresponding to the results obtained with native hirudin. The effects on the haemostatic system were evaluated. Thrombin time and partial thromboplastin time were prolonged dependent on the r-hirudin plasma level. Platelet counts, fibrinogen level and fibrinolytic system were unchanged. Bleeding time was not prolonged. After administration of r-hirudin in case of chronic DIC, fibrinogen level, platelet counts and fibrin monomers transiently returned to normal values.