Use of droperidol and fentanyl for analgesia and sedation in primates

A combination of droperidol and fentanyl produces qualitatively similar pharmacologic effects in dogs and primates. Unlike the dog, however, primates did not appear to respond to auditory stimuli. As a result of the analgesic and sedative or tranquil state produced in primates, the animals were easily handled and tolerant of painful stimuli. The principal desirable features of the combination were high analgesic and sedative potency and a rapid onset of action following intramuscular administration. High doses produced respiratory depression. However, this effect was easily reversed by administering nalorphine hydrochloride.