Comparative evaluation of prophylactic use of pregabalin, gabapentin and diclofenac sodium for prevention of succinylcholine-induced myalgia

Abstract

Succinylcholine a depolarizing muscle relaxant with rapid onset, predictable course and short duration of action is associated with myalgia. The aim of this study is to evaluate the efficacy of pregabalin, gabapentin and diclofenac on the incidence and severity of succinylcholine-induced myalgia. Tertiary Care Teaching Hospital. A total of 120 patients undergoing laparoscopic cholecystectomy were randomly assigned into three groups: Pregabalin group received 150 mg of pregabalin, gabapentin group received 600 mg of gabapentin and diclofenac group received 100 mg of diclofenac sodium orally 2 h prior to surgery. Anesthesia was induced with fentanyl 3 μg/kg, propofol 2-2.5 mg/kg and succinylcholine 1.5 mg/kg and was maintained with oxygen with sevoflurane in the air and intermittent vecuronium bromide. A blinded observer recorded post-operative pain scores on visual analog scale at different time intervals and myalgia at 24 h. Post-operative pain relief was provided with fentanyl based patient-controlled analgesia. Fentanyl consumption in 24 h was recorded as a primary outcome. Patients' characteristics and total fentanyl consumption were compared using one-way ANOVA followed by post-hoc test. Pain score was compared amongst the groups using Kruskal Wallis test. The myalgia occurred in 15, 14 and 13 patients in pregabalin, gabapentin and diclofenac sodium group respectively (P > 0.85). Patients in diclofenac group had significantly higher fentanyl consumption (674.85 ± 115.58 μg) compared with pregabalin group (601.87 ± 129.57 μg) (95% confidence interval [CI] = 34.8-120.7) and gabapentin group (612.29 ± 105.12 μg) (95% CI = 14.9-170.5). However, there was no significant difference in fentanyl consumption between pregabalin and gabapentin groups (95% CI = -34.8-120.7). There was a significant difference in visual analog score at time points 12, 18 and 24 h among the study groups. Pre-treatment with pregabalin, gabapentin and diclofenac had equal efficacy in reducing the incidence and severity of succinylcholine-induced myalgia. However, pre-treatment with pregabalin and gabapentin decreased post-operative pain scores and fentanyl consumption.