Comparison of the Efficacy and Tolerability of Tramadol, Pethidine and Nalbuphine in Children with Postoperative Pain

Abstract

The analgesic efficacy and tolerability of tramadol, pethidine and nalbuphine were compared in this randomised study. 75 children aged 2 to 12 years with moderate or severe pain after mainly lower abdominal surgery received either tramadol 2 mg/kg (n = 25), pethidine 1 mg/kg (n = 25) or nalbuphine 0.1 mg/kg (n = 25) by intramuscular injection as soon as pain was expressed. An additional bolus of half the initial dose was administered 30 to 60 minutes later if analgesia was inadequate. Further doses equal to the initial bolus were given if pain requiring retreatment reappeared, up to a maximum daily dose of tramadol 12 mg/kg, pethidine 5 mg/kg and nalbuphine 1 mg/kg. Drug dosages were recorded in the patient records; the study was therefore regarded as an open trial. 60 minutes after the initial dose, children in all 3 treatment groups had either no or only slight pain. This level of efficacy was present at 30 minutes postdose in patients in the tramadol and pethidine groups and was maintained for 24 hours. In the nalbuphine group, pain of moderate intensity reappeared in 1 (4%) child 30 minutes after administration of the initial dose and in 2 (8%) children 6 hours after the initial dose. The number of repeat doses required to control pain was lowest with tramadol and highest with nalbuphine; 40% of patients receiving nalbuphine required 2 or more doses of medication compared with 28% of pethidine-treated patients and 4% of tramadol-treated patients. Overall pain relief was rated by investigators as ‘excellent’ in 40% of patients receiving tramadol, in 32% of patients receiving pethidine and in 24% of patients receiving nalbuphine, and as ‘very good’ in 48, 44 and 52% of patients, respectively. Reductions in blood pressure, respiratory rate and heart rate, and increases in arterial oxygen saturation, were minimal and were similar in all 3 treatment groups. Vomiting was the only adverse event reported, and this occurred in 1 patient treated with tramadol. Tramadol 2 mg/kg appears to be an effective and well-tolerated analgesic agent in children with postoperative pain.