[Studies on the interaction of Phenprocoumon with Diazepam and with Nitrazepam (author's transl)].

The influence of Diazepam and Nitrazepam on the anticoagulating activity of Phenprocoumon was studied in rats. It was found that the repeated oral application of Diazepam or Nitrazepam during the treatment with Phenprocoumon did not change the adjusted prothrombin time. The prothrombin time was considerably shortened when the application of Diazepam or Nitrazepam was stopped although Phenprocoumon was still applied. Furthermore, the influence of Chlordiazepoxid, Diazepam and Nitrazepam on the normal prothrombin time was studied. It was found that the treatment with benzodiazepine derivatives had no influence upon the prothrombin time, not only during the treatment, but also after the treatment was stopped.