Anticoagulant effect and plasma kinetics of fluorophenindione after a single dose in man.

After administration of a single loading dose (80 mg p.o.) of fluorophenindione, the prothrombin level decreased to 37% in 24 h, and the effect lasted for 48 h. Accordingly, fluorophenindione can be classified as an anticoagulant with an ""intermediate'' effect. Its elimination half-life was 31 h, which is longer than that of phenindione, because of the greater stability of the fluorinated derivate.