Comparison of analgesic efficacy of acetaminophen monotherapy versus acetaminophen combinations with either pethidine or parecoxib in patients undergoing laparoscopic cholecystectomy: a randomized prospective study.

Aim To investigate analgesic effect of three different regimens of combination of analgesics administered to patients undergoing laparoscopic cholecystectomy. Methods Patients undergoing laparoscopic cholecystectomy were randomly allocated to one of three groups on admission, depending of a prescribed post-operative analgesic regimen. Patients allocated to the group A received a combination of intravenous (IV) acetaminophen and intramuscular (IM) pethidine, patients in the group B received a combination of IV acetaminophen and IV parecoxib, and the patients of the group C received IV acetaminophen monotherapy. Analgesic therapy was administered at regular intervals. Pain was evaluated utilizing the numeric rating scale (NRS) at 5 time points: the first assessment was done at 45 minutes, the second, third, fourth and fifth at 2, 6, 12, and 24 hours post-administration, respectively. Postoperative pain intensity was measured by NRS within the groups and between the groups at each time they analysed using one-way repeat measured ANOVA and Post Hoc Test-Bonferroni Correlation. Results A total of 316 patients were enrolled. The analgesic regimens of groups A and B (combination regimens consisting of IV acetaminophen and intramuscular pethidine and IV acetaminophen and IV parecoxib, respectively) were found to be of equivalent efficacy (p=1.000). In contrast, patients in group C (acetaminophen monotherapy) had higher NRS scores, compared to both patients in groups A (p<0.01) and B (p<0.01). Conclusion This study confirms the notion of a significant opioid-sparing effect of parecoxib in postoperative pain management after laparoscopic cholecystectomy.