Relative analgesic potency of intramuscular heroin and morphine in cancer patients with postoperative pain: a preliminary report.

The results of this study in postoperative patients have, thus far, revealed little that was not expected from a review of the literature. Heroin hydrochloride appears to be about two to three times more potent than morphine sulfate as an analgesic, to act more promptly and to have a slightly shorter duration of action. There is a suggestion that heroin may have a somewhat different spectrum of side effects and mood effects compared to morphine, but the effects of both drugs on mood were inversely correlated with the patients' feelings at the time of drug administration. Regardless, as a group, patients responded to both drugs with significantly improved moods. A lag time between the peak intensity of analgesic and mood effects of both heroin and morphine suggest a dissociation between these effects. Whether or not these early impressions will be reinforced as this study proceeds, and whether or not the effects of the drugs in patients with chronic pain due to advanced cancer will be any different than in these patients with postoperative pain, remains to be seen.