The analgesic interaction of tramadol and morphine in rats: An isobolographic study.

In order to assess possible synergistic antinociceptive interactions, the analgesic effects of intra-peritoneal tramadol and morphine administered either separately or in combination were determined using tail-flick latency test following exposure to radiant heat in rats. Groups of eight male Sprague-Dawley rats received either tramadol (3.90, 7.00, 12.50, and 22.20 mg kg-1) and morphine (1.26, 2.25, 4.00 and 7.10 mg kg-1) or a combination of tramadol and morphine (4 different combinations). The baseline latency was obtained before drug injection for each rat, then at 15, 30, 45, 60 and 75 min after injection. The effective dose (ED)50 for either tramadol or morphine individually was 11.70 mgkg-1 and 2.26 mg kg-1, respectively. Based on isobolographic analysis, the ED50 values obtained by drug combination were significantly less than the calculated additive values; which indicates that the co-administration of tramadol and morphine produces synergistic antinociception in the radiant heat tail-flick assay. Combination of morphine and tramadol administered intra-peritoneally can be used for the control of acute pain in rats.

Evaluation of guide wire cannulation in reduced risk of post - ERCP pancreatitis and facilitated bile duct cannulation.

BACKGROUND: Pancreatitis is most common complication of post-ERCP and needs to admission at least for one day. The purpose of this study was to assess the efficacy of guide wire for better common bile duct (CBD) cannulation for reducing post-ERCP pancreatitis. METHODS: From April 2010 through March 2011, the patients who needed ERCP and referred to Shahid Beheshti and Rouhani Teaching Hospital were entered into the study. Guide wire cannulation (65 subjects) as case group and 78 cases with standard cannulation as control group were performed on them randomly. Data from these cases were collected and analyzed. RESULTS: One hundred eighteen (82.5%) patients were females and 28 (17.5%) were males. The mean age of these patients was 56.5±16.8 years. Post- ERCP pancreatitis rate in guide wire group was 6 (9.2%) and in the standard group was 12 (15.4%) (p=0.269). Successful cannulation in these two groups was 67.7% and 67.9%, respectively (p=0.974). CONCLUSION: The results show that post- ERCP pancreatitis rate in both groups are similar. Other studies with large number of cases are required to confirm our results.