Comparative study of tramadol versus NSAIDS as intravenous continuous infusion for managing postoperative pain

Abstract

We compared the analgesic efficacy and safety of tramadol, a new pure agonistic central analgesic, with that of three nonsteroidal anti-inflammatory drugs (NSAIDs) in the control of postoperative pain. A total of 160 patients undergoing abdominal hysterectomy participated in this randomized, double-blind study. Four treatment groups were established: tramadol, metamizole, ketorolac, and lysine clonixinate, with 40 patients in each group. Analgesics were administered using continuous infusion plus patient-controlled analgesia. During this 24-hour study, pain was assessed by using a visual analog scale. The number of boluses required per patient, the number of patients requiring supplementary analgesia, the presence of nausea or vomiting, the need for antiemetics, and an evaluation of overall efficacy also were recorded during the first 24 hours after surgery. The analgesic efficacy of tramadol was found to be greater than that of the three NSAIDs. Tramadol also was statistically significantly better than the other three agents with regard to the number of boluses required per patient (1.6 versus 4.4 for metamizole, 4.5 for ketorolac, and 5.3 for lysine clonixinate) and the number of patients requiring supplementary analgesia (1 patient versus 5 for metamizole, 11 for ketorolac, and 11 for lysine clonixinate). Nausea and vomiting were common in all four groups, especially in patients treated with metamizole, but the need for antiemetics was significantly lower with tramadol and lysine clonixinate. With regard to overall efficacy, as rated by the physician, excellent and very good results were obtained in 79.5% of the patients in the tramadol group, compared with 57.5%, 57.5%, and 50% of those in the metamizole, ketorolac, and lysine clonixinate groups, respectively ( P < 0.05 or better). The results of this study confirm that tramadol, a central analgesic, is better for controlling postoperative pain than the NSAIDs with which it was compared.