Effects of narcotic analgesic drugs on human Oddi's sphincter motility

AIM: To assess the effects of intramuscular analgesics(morphine, Ap-237, pethidine and tramadol) on humanOddi's sphincter motility with choledochoscope manometry.METHODS: A total of 70 patients having T tubes aftercholecystectomy and choledochotomy were assessed bycholedochoscope manometry. They were randomly dividedinto morphine group, Ap-237 group, pethidine group andtramadol group. Basal pressure of Oddi's sphincter (BPOS),amplitude of phasic contractions (SOCA), frequency ofphasic contractions (SOF), duration of phasic contractions(SOD), duodenal pressure (DP) and common bile ductpressure (CBDP) were scored and analyzed. All narcoticanalgesic drugs were administered intramuscularly.RESULTS: Levels of BPOS, SOCA and SOF were increasedafter injection of morphine and Ap-237 (P<0.05), level of CBDPwas increased from 4.97+3.87 mmHg to 8.62+7.43 mmHg(10 min later) and 7.32+5.95 mmHg (20 min later) afterinjection of morphine (P<0.01). No apparent changeoccurred after intramuscular injection of pethidine. Level ofBPOS was increased from 7.01+5.50 mmHg to 2.87+2.78 mmHg10 min after injection of tramadol and SOCA was decreasedfrom 63.34+35.29 mmHg to 45.90+27.86 mmHg (10 minlater, P<0.05) and 35.97+24.30 (20 min later, P<0.01) afteradministration of tramadol.CONCLUSION: All these findings indicate that Oddi'ssphincter manometry via choledochoscope is a practicaland new way to study the dynamics of Oddi' s sphincter.The regular dose of morphine and Ap-237 could increaseBPOS, SOF and SOCA. Morphine could increase the levelof CBDP, demonstrating an excitatory effect on the sphincterof Oddi. Pethidine had no effect on Oddi's sphincter motility.Tramadol shows an inhibitory effect on the motility of thesphincter of Oddi and decreases levels of BPOS and SOCA.