Duration of action of analgesic supplements to anesthesia. A double-blind comparison between morphine, fentanyl and sulfentanil.

In a double-blind trial, in a total of 45 patients, sulfentanil was compared with fentanyl and morphine in equipotent doses, as a narcotic supplement to anesthesia. Initially, morphine was shown to have a significantly longer duration of effect than fentanyl and sulfentanil, which for the first 3 doses had similar durations of action to each other. Later doses of fentanyl, however, had an extended effect, presumably because of cumulation. This was not seen with sulfentanil.