Clinical pharmacological studies with 6-azidomorphine

The intravenous (i.v.) administration of 4 mug/kg 6-deoxy-6-dihydroazido-isomorphine (6-AM) base to healthy, young adult male volunteers caused no circulatory and relatively little, short-lasting respiratory depression. Of the ten volunteers all felt lightheaded, two became euphoric and when they became ambulatory at the end of the experiment, three vomited and two other became nauseated. The intramuscular (i.m.) administration of the same dose of 6-AM had considerable analgesic effect against various types of experimental pain. It was more effective against ischemic pain, than against pain induced by electrical stimulation of the earlobe or the tooth pulp and it effected severe pain more than mild or moderate pain. In the six subjects investigated, 6-AM produced significant myosis. Of the 16 subjects who received 4 mug/kg 6-AM i.m. five experienced mild euphoria, two felt lightheaded, six became pale and sweaty in the course of the experiments carried out in the sitting position. When they becam ambulatory after the completion of the experiments, two subjects vomited and six others became nauseated. The findings of this study indicate that 6-AM causes less circulatory and respiratory depression than is to be expected from equianalgetic doses of morphine. Its other side effects (e.g., nausea, vomiting) are also less frequent and severe than those encountered after the administration of comparable doses of morphine to ambulating volunteers.