[Initiation of oral anticoagulant treatment: comparison between different dosage regimens of warfarin and phenprocoumon]. / Initialphase der oralen Antikoagulanzientherapie: Vergleich verschiedener Dosierungen von Warfarin und Phenprocoumon.

ABSTRACT

A high "loading dosage" is often given during initiation of oral anticoagulant treatment in order to reach sufficient anticoagulation within short time. Increased bleeding risk as well as a transient prothrombotic tendency are complications of this treatment schedule. The aim of our study was to find proper dosage regimens of phenprocoumon and warfarin allowing initiation of oral anticoagulant treatment in a short time. For 50% of the patients 7.5 mg warfarin daily resulted in stable INR values within 4 days. Patients receiving higher (10 mg) or lower (5 mg) daily dosages of warfarin or 6 or 9 mg phenprocoumon daily during the first days of therapy reached the therapeutic range significantly later. Furthermore, no significant differences of prothrombin fragment F 1+2 were observed, indicating that no enhanced thrombin formation occurred. Thus, initiation of oral anticoagulant treatment using 7.5 mg warfarin daily is a simple and safe dosage regimen.