%0 Journal Article %A Claus W. Reichle %A Gene M. Smith %A Joachim S. Gravenstein %A Spyros G. Macris %A Henry K. Beecher %T COMPARATIVE ANALGESIC POTENCY OF HEROIN AND MORPHINE IN POSTOPERATIVE PATIENTS %D 1962 %J Journal of Pharmacology and Experimental Therapeutics %P 43-46 %V 136 %N 1 %X Morphine phosphate, 10 mg per 70 kg of body weight, was used as a standard in an evaluation of pain relief produced by four different dosages of heroin hydrochloride: 6, 4, 2 and 1 mg/70 kg of body weight. The subjects were 522 patients with steady incisional pain due to major thoracic, abdominal or orthopedic surgery. The methods of assessing pain relief, and methods of comparing the pain relief produced by morphine and heroin, were described. The results of the present study showed that heroin was approximately two to four times as potent as morphine with respect to relief of moderate, severe or very severe postoperative pain during the first 150 minutes after injection. The amount of heroin needed to match the analgesic potency of morphine (10 mg) in the group comparisons ranged from 2.3 mg to 5.2 mg. That variation was due partly to the fact that the analgesic power of heroin, relative to that of 10 mg of morphine, was greater early during the post-injection period than it was late during the post-injection period. It was pointed out that the difference between heroin and morphine with respect to analgesic time course indicates that there is no single value of heroin which is equianalgesic to 10 mg of morphine. The discrepancy between the present results and those of an earlier study (using the von Frey hair technique for producing experimental pain) was mentioned. %U https://jpet.aspetjournals.org/content/jpet/136/1/43.full.pdf