Role of parecoxib in pre-emptive analgesia: comparison of the efficacy and safety of pre- and postoperative parecoxib in patients undergoing general surgery.

Management of acute postoperative pain remains sub-optimal despite the availability of multiple analgesics and improved pain management strategies (with nearly 80 % of patients reporting moderate to extreme pain following surgery). To evaluate the role of parecoxib as a pre-emptive analgesic in patients undergoing general surgery, the present study was undertaken. Eighty patients of either sex, aged 18 to 70 years, requiring elective ambulatory general surgery like hernioplasty, appendicectomy, cholecystectomy, etc, were enrolled in this prospective, randomised, assessor-blind, parallel-group, comparative trial. Eligible patients were randomised to receive a single dose of 40 mg of parecoxib IM/IV either 30-45 minutes prior to induction of anesthesia (pre-emptive analgesia) or in the postoperative period when one reported pain or when the effects of anesthesia were worn off (whichever was earlier). The primary measures of efficacy were pain intensity scores measured on a visual analog scale (VAS) and pain relief before and after therapy. Adverse event monitoring, physical examination and changes in laboratory tests, chest x-ray and ECG were used to evaluate safety. A comparison of the pain intensity scores between the two groups revealed that patients treated with parecoxib preoperatively did not complain of pain in the entire postoperative period up to 12 hours. Mild pain (1.05+/-1.36) was reported by patients in this group only at the 24 hours assessment. On the other hand, patients treated with parecoxib in the postoperative period, experienced severe pain at baseline, which declined gradually up to 12 hours. The difference in the pain intensity scores between the two groups was statistically significant at all the time intervals from 0 hour to 24 hours. All the 40 patients (100%) in the pre-operatively treated group reported total pain relief at 12 hours compared to only 22 patients (55%) in the postoperative period. At 24 hours total pain relief was reported by 70% of the patients in the pre-operatively treated group, compared to only 20% (8) patients in the postoperatively treated group. The difference between the two groups was statistically significant in favour of the pre-operatively treated group (p<0.05). Present results suggested that pre-operative administration of parecoxib was more effective than a postoperative use in providing pain relief in postoperative period in patients undergoing elective general surgical procedures. Both the regimens were well tolerated. Based on the above data, it appears that pre-operative dose of parecoxib 40 mg IV/IM is a useful optionfor pre-emptive analgesia in general surgical practice.