Cólico biliar inducido por morfina / Morphine induced biliary pain: case report

Morphine produces contraction of Oddi’s sphincter, which can be severe and of longer duration in some pathological conditions. This exaggerated response can manifest as a colicky biliary pain, frequently accompanied by a dramatic increase in hepatic enzymes. We report a 32 years old female who consulted in the emergency room for severe low abdominal pain of gynecologic origin, which was completely controlled by morphine. However, she presented a sudden epigastric colicky pain irradiating in the back, which persisted for several hours in spite of the repeated administration of analgesics. Transaminases elevated from previously normal value to over 1,000 U/L, and returned to the normal level without further treatment after several days. Magnetic resonance cholangiography showed normal fine bile duct, without stones. This transient increase in hepatic enzymes was considered as a consequence of high biliary pressure secondary to morphine-induced spastic contraction of Oddi’s sphincter and a consecutive hepatocellular necrosis.

Lack tolerance of morphine induced spasm of Guinea pig sphincter of Oddi

To determine whether guinea pigs chronically exposed to morphine would develop tolerance to the morphine-induced contraction of the sphincterof Oddi (SO), adult male guinea pigs were implanted with morphine pellets (100 mg morphine). The effect of increasing IV doses of morphine on the SO was assessed by determining the duration of which saline perfusate stopped flowing into the duodenum of morphine-treated guinea pigs (MTGP) vs monimplanted animals (non-MTGP). Isolated bovine and guinea pigs SO were also challenged with morphine. Int the in vivo experiments the spasmogenic response of the SO from MTGP to morphine was greater than of SO from non-MTGP. However, morphine had no effect on isolated SO. These results indicate that chronic morphine exposure does not results in tolerance of the SO to the spasmogenic effects of morphine. On the contrary, chronic morphine even sensitized the SO to morphine, in addition, the in vitro data indicated that morphine does not act directly on the smooth muscle of SO to cause spasmogenic effect