phenprocoumon and Dysthymic-Disorder

Carbamazepine inhibits warfarin and dicoumarol anticoagulation through induction of cytochrome P450-enzymes. Inhibition of phenprocoumon anticoagulation by carbamazepine has been supposed in some reviews, however, without hard empirical evidence. We report a patient who was anticoagulated with phenprocoumon in whom carbamazepine produced a dramatic increase in prothrombin time ratio (Quick). After discontinuation of carbamazepine, Quick-values returned to therapeutic levels. Valproate did not affect phenprocoumol's anticoagulant properties. The potentially hazardous carbamazepine-phenprocoumon interaction should be emphasized in reference drug manuals.

Topics: Anticoagulants; Antimanic Agents; Carbamazepine; Drug Interactions; Dysthymic Disorder; Female; Humans; Middle Aged; Phenprocoumon; Prothrombin Time; Venous Thrombosis