PAIN RELIEF BY INTRATHECALLY APPLIED MORPHINE IN MAN

Eight patients who had severe intractable pain in the back and legs secondary to malignancies of the genitourinary tract with invasion of the lumbosacral plexus were selected for study. Two of the eight patients reported complete relief of pain after separate injections of morphine and physiologic saline solution, although the mean duration of relief after morphine injection was 15 hours, whereas that after injection of physiologic saline solution was seven hours. The other six patients reported complete relief from pain after the morphine injections. Relief lasted 12 to 24 hours, the average duration being 20 hours. Elapsed times from instillation of the drug to its maximal effect ranged from about 15 to 45 min. Increasing the dose of morphine to 1.0 mg did not prolong the relief proportionately. In contrast to the good response to morphine, there was no improvement after nine injections of physiologic saline solution. The results of repeated injections of either morphine or physiologic saline solution in the same patient were strikingly reproducible.