New adjuvants to enhance anticoagulant activity of warfarin.

New adjuvants of warfarin anticoagulant activity have been developed. These compounds, which are 1,4-methano-1,2,3,4-tetrahydroanthracene-9,10-diol derivatives, act synergistically with warfarin to potentiate its anticoagulant effect. None of the compounds tested is an effective oral anticoagulant in the absence of warfarin.