[Subcutaneous recombinant hirudin in the treatment of deep venous thrombosis. A pharmacokinetic study].

Recombinant hirudin (HBW 023) has a pure and specific antithrombotic activity. It could be more effective than heparin in the treatment of deep venous thrombosis. Its half life is about three hours when administered intravenously which requires continuous infusion whereas subcutaneous administration can ensure stable plasma concentrations and antithrombotic activity over a period of approximatively 12 hours. The aim of the study was to check the safety and clinical and radiographic efficacy of recombinant hirudin administered subcutaneously to patients with recent deep venous thrombosis and to analyse the pharmacokinetics of the product and its effects on tests of coagulation. Ten patients were treated with 0.75 mg/kg of subcutaneous recombinant hirudin twice a day for 5 days. Anticoagulation was performed with standard heparin and acenocoumarol. Bilateral phlebography, pulmonary angiography or ventilation and perfusion scintigraphy were carried out before and on the 5th day of recombinant hirudin treatment. The activated cephalin time and standard anticoagulant tests and the plasma kinetics of recombinant hirudin were assayed between the 1st and 12th hour on the first and fifth days of treatment. The clinical course was simple in all but one patient who had a recurrence of pulmonary embolism on the 4th day justifying thrombolytic treatment. No haemorrhagic complications or secondary biological effects were observed. On the 5th day, control phlebography was unchanged or improved in all patients. The peak plasma concentration of recombinant hirudin was observed between the 3rd and the 4th hour following subcutaneous injection. The activated cephalin time was increased in parallel with increased concentrations of recombinant hirudin.(ABSTRACT TRUNCATED AT 250 WORDS)