Abstract
An assessment of the general properties of fentanyl and phenoperidine has been made by including them in the continuing trial of drugs given before anaesthesia. Fentanyl and phenoperidine both differed from morphine in that they produced much less sedation, while the incidence of restlessness was greater after fentanyl than it was with morphine or phenoperidine. None of the drugs had any remarkable effect on cardiovascular system stability, although both fentanyl and phenoperidine were associated with a notable incidence of tachycardia. Neither drug showed as strong an emetic effect as did morphine, phenoperidine causing the least sickness while fentanyl occupied an intermediate position. The effect of addition of droperidol to fentanyl and phenoperidine was to increase the sedative effect over that of either drug given alone, whilst the unpleasant subjective effects and restlessness associated with droperidol given alone were also reduced by combination with the opiates. The anti-emetic effect of droperidol was confirmed.