The post-operative analgesic effects of a combination of gabapentin and paracetamol in patients undergoing abdominal hysterectomy: a randomized clinical trial

Background: The aim of the present study was to compare the effects of a combination of gabapentin and paracetamol with gabapentin alone and placebo on post-operative pain and morphine consumption. Methods: Seventy-five ASA I-II patients undergoing abdominal hysterectomy were included in the study and randomly divided into three groups. Placebo capsules (Group I, n = 25), 1200 mg of gabapentin (Group II, n = 25), or 1200 mg of gabapentin and 20 mg/kg paracetamol in combination (Group III, n = 25) were administered 1 h prior to surgery. Anaesthesia was standardized for all patients. Non-invasive arterial pressure, heart rate, respiratory rate, peripheral oxygen saturation, morphine consumption, nausea and vomiting, visual analogue scale-pain intensity scores (VAS-PI) and sedation scores were recorded at 1, 2, 4, 6 and 24 h following the operation. Results: Morphine consumption at 24 h was 66.60 +/- 11.49 mg, 42.74 +/- 12.33 mg and 30.50 +/- 11.55 mg, respectively, in groups I, II and III (P < 0.05). Post-operative VAS-PI scores at movement and at rest were decreased with gabapentin and even more with a combination of gabapentin and paracetamol. Post-operative sedation scores were higher in groups II and III during the initial 4 h while these scores were higher in group I at 24 h. Conclusions: The single dose of gabapentin as well as a combination of gabapentin and paracetamol decreased the opioid requirement and increased the patients' satisfaction post-operatively.