Comparative evaluation of prophylactic use of pregabalin, gabapentin and diclofenac sodium for prevention of succinylcholine-induced myalgia: a randomized, double-blinded study.

Background: Succinylcholine a depolarizing muscle relaxant with rapid onset, predictable course and short duration of action is associated with myalgia.

Objective: The aim of this study is to evaluate the efficacy of pregabalin, gabapentin and diclofenac on the incidence and severity of succinylcholine-induced myalgia.

Methods: Tertiary Care Teaching Hospital. Methods: 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. Methods: 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.

Results: 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.

Conclusions: 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.