Efficacy of intravenous paracetamol compared to dipyrone and parecoxib for postoperative pain management after minor-to-intermediate surgery: a randomised, double-blind trial.

Background And Objective: Paracetamol has a well established pharmacological profile, but its postoperative efficacy is in question. This double-blind, placebo-controlled study was designed to compare the efficacy of intravenous paracetamol with other intravenous non-opioids as part of a multimodal concept for perioperative pain therapy.

Methods: Patients undergoing minor-to-intermediate surgery under general anaesthesia were randomly assigned to receive infusions of paracetamol (1 g every 6 h), dipyrone (1 g every 6 h), parecoxib (40 mg every 12 h) separated by infusions of physiological saline 0.9%, or placebo (0.9% saline every 6 h), respectively, for at least 48 h as part of a multimodal pain concept. Patient-controlled piritramide was administered as rescue medication. Dependent variables were recorded 1, 6, 18, 30 and 42 h after extubation and 1 week after surgery. Surgical and associated pain was scored as the primary outcome on a visual analogue scale. Additionally, time to first dose and total piritramide dosage, satisfaction, respiratory depression, nausea, vomiting, sedation, itching and sweating were recorded.

Results: A total of 196 patients were recruited. The efficacy of paracetamol was similar to that of the other non-opioid analgesics. Surgical pain was reduced with all non-opioids compared to placebo; there was no effect on associated pain. Piritramide dosage and incidence of side effects were not reduced.

Conclusion: Intravenous paracetamol has equivalent efficacy to non-opioids dipyrone and parecoxib that improves postoperative pain therapy when used as part of a multimodal concept after minor-to-intermediate surgery.