Effect of Morphine and butorphanol on gallbladder emptying.

In the search for the most appropriate analgesic for patients with biliary tract and pancreatic pain, the authors compared the effect of morphine and the opiate agonist-antagonist butorphanol on gallbladder contraction and emptying stimulated by cholecystokinin octapeptide. Morphine markedly inhibited gallbladder emptying while butorphanol only slightly delayed it. Compared with morphine, the effect of butorphanol was minimal; the latter, therefore, seems to be a suitable analgesic for the treatment of pain of biliary tract or pancreatic origin.