Effects of butorphanol, nalbuphine, and fentanyl on intrabiliary tract dynamics

The effects of equianalgesic doses of fentanyl citrate (100 micrograms; n = 20), butorphanol tartrate (2 mg; n = 20), and nalbuphine hydrochloride (10 mg; n = 16) on biliary tract dynamics were examined in patients anesthetized with enflurane-nitrous oxide. After removal of the gall bladder, the common bile duct or cystic duct remnant was cannulated with an 18-gauge catheter. Using a modified Caroli apparatus, control measurements of flow through the common bile duct into the duodenum over 60 sec and resting intrabiliary tract pressure were obtained. Patients then were given one of the drugs intravenously and measurements were repeated 5 min later. Flow rates decreased 35%, 21%, and 13% after fentanyl, butorphanol, and nalbuphine, respectively. Similarly, resting intrabiliary tract pressures increased by 23%, 12%, and 6%, respectively. All changes were statistically significant (P less than 0.05) except for the increase in intrabiliary tract pressure after nalbuphine. Likewise, the incidence of decreases in flow rate or increases in intrabiliary tract pressure more than 20% was greater after fentanyl than after either butorphanol or nalbuphine. Agonist-antagonist analgesics may be advantageous in patients with known or suspected biliary tract disease.