[Studies on the interactions of chlordiazepoxide, nitrazepam, and diazepam with phenprocoumon (author's transl)].

The interaction of benzodiazepine derivatives with phenprocoumon (Marcumar) was investigated after a single dose of the combination of phenprocoumon/diazepoxide (Librium), phenprocoumon/diazepam (Valium) and phenprocoumon/nitrazepam (Mogadan) had been applied to rats. By means of the high pressure liquid chromatography (HPLC) the change of concentration of these pharmaceutical agents per unit time in serum was determined and related to the corresponding change of prothrombin-time. Hence it can be concluded that the benzodiazepine derivatives influence the distribution of phenprocoumon in the organism.