[Action of central depressants on the nitrous oxide anesthesia (author's transl)]

The synergistic action of seven central depressants three benzodiazepines, two neuroleptics on barbiturate and morphine on the anesthetic activity of nitrous oxide was studied in mice. The benzodiazipines and among them nitrazepam and flunitrazepam were found to be the most potent drugs in this respect; morphine on the other hand was innefective even in toxic doses. There was a significant difference in the slope of log dose-response curves; these curves were much steeper for pentobarbitone, droperidol and chlorpromazine than for nitrazepam, flunitrazepam, and diazepam. The theoretical and practical implications of this difference are discussed.