Post-operative Analgesic and Opioid-sparing Effect of a Single-dose Pre-operative Oral Pregabalin in Gynaecological Surgeries

BACKGROUND: Post-operative pain treatment is a major challenge in our environment. Opioids may cause respiratory depression post-operatively. Therefore, any combination of opioid and non-opioid analgesics that provides quality post-operative pain control and reduces opioid consumption with its attendant side effects will be highly desirable. OBJECTIVES: The aim of this article is to evaluate analgesic benefits and opioid-sparing effects of pre-operative oral pregabalin in patients who undergo abdominal gynaecological surgeries. MATERIALS AND METHODS: A prospective randomized double-blind placebo-controlled study is carried out at University of Ilorin Teaching Hospital, Kwara State, Nigeria. Eighty-two patients scheduled for gynaecological surgeries were randomized into two equal groups. The patients in the control and study groups received a placebo drug and oral pregabalin 150 mg, respectively, 1 h before induction of general anaesthesia. Post-operative pain intensity using a five-point Verbal Rating Scale, time to first request for analgesia, and 24 h post-operative pethidine consumptions were assessed. Mean values were compared using Student’s t-test. Categorical data were compared with the χ(2) test. Level of significance was set at 5% (0.05) and power of the study was 80%. RESULTS: Demographic characteristics were comparable between the two groups. The median pain score was 0–2 (no pain–moderate pain) throughout the study. Post-operative static and dynamic pain scores at 1, 4, and 12 h were significantly higher in the placebo group (<0.001). Twenty-four hours post-operatively, there were no significant differences in static and dynamic pain scores between the two groups (P=0.131 and P=0.384, respectively). Time to first analgesic requirement and total pethidine consumed within 24 h post-operative were 47 ± 19 vs. 258 ± 137 min (P=0.001) and 326.19 ± 62.70 vs. 192.86 ± 55.84 mg (P=0.001) in the control and study groups, respectively. The pre-operative use of pregabalin reduced post-operative opioid requirement by 40.9% in the study group. Nausea and vomiting were more common in the placebo group, whereas dizziness, blurring of vision, and sedation were more common in the pregabalin group. CONCLUSION: A single pre-operative dose of 150 mg oral pregabalin had significantly greater analgesic effects compared with placebo and reduced post-operative opioid requirements in patients undergoing myomectomy or total abdominal hysterectomy. It should be considered an adjuvant in multimodal pain management regimens following gynaecological surgeries.