[Problems of heparin dosage].

Administration of heparin by continuous intravenous infusion is, so far as bleeding complications are concerned, safer than intermittent injection. Recurrence of venous thromboembolism during infusion is rare if the APTT is prolonged to 1 1/2-2 1/2 times the control value. The efficacy of low-dose heparin in the primary prevention of venous thromboembolism in medical patients remains unproven. On the other hand, adjusted-dose subcutaneous heparin treatment provides an effective alternative to oral anticoagulants in the long-term treatment of venous thrombosis.