BISHYDROXYCOUMARIN, ETHYL BISCOUMACETATE, AND 4-HYDROXYCOUMARIN ANTICOAGULANT NO. 63

Bishydroxycoumarin (dicumarol®) has been used clinically as an anticoagulant for 10 years. 1 Recently two other coumarin compounds, ethyl biscoumacetate (tromexan®) 2 and 4-hydroxycoumarin anticoagulant No. 63 3 (hereafter in this paper designated as anticoagulant No. 63), have been investigated experimentally and clinically with the hope that they might have advantages over bishydroxycoumarin for clinical use in anticoagulant therapy (Fig. 1). Like bishydroxycoumarin, these two coumarin compounds induce hypoprothrombinemia, which is defined for this paper as that coagulation defect indicated by prolongation of the one-stage prothrombin time. Also, as is the case with bishydroxycoumarin, other effects or untoward reactions not related to the coagulation defect have not been noted, except for rare mild allergic reactions and occasional mild gastrointestinal irritation. It is well known that the response of the one-stage prothrombin time varies greatly among different patients who receive certain fixed doses of bishydroxycoumarin. Body weight, nutritional status, gastrointestinal disease