Difference in the Heparin-Neutralizing Effect of Protamine and Polybrene as Tested by Thrombotest

Abstract

1. Thrombotest as well as other one-stage prothrombin assays is influenced by heparin in vitro and in vivo. After an average dose of heparin intravenously, the effect on thrombotest lasts for about 8 hours. 2. When heparin is added to citrated blood in Vitro, polybrene and protamine are both able to correct the prolonged thrombotest time. 3. Polybrene is not able to correct the prolonged thrombotest values in blood from heparinized subjects, whereas protamine gives complete correction. Both are able to correct the prolonged thrombin time. 4. When 0.06 mg of protamine ml is added to blood from patients receiving combined therapy with heparin and an oral anticoagulant, the effect of heparin is neutralized and thrombotest values reflect only the effect of the oral anticoagulant.