A Randomized Double-Blind Placebo-Controlled Study to Compare Preemptive Analgesic Efficacy of Novel Antiepileptic Agent Lamotrigine in Patients Undergoing Major Surgeries

Background: If postoperative acute pain remains unrelieved, it may result in significant morbidity and mortality. Preemptive analgesic initiated before surgery offers premature analgesia even before exposure to an initial noxious stimulus bestowing effective postoperative analgesia. In developed countries, it is regularly practiced as a part of well-defined protocol. In our country however, only a few centers practice it and that too irregularly and with undefined protocol. Few studies support preemptive analgesic efficacy of novel antiepileptic agent gabapentin. Though lamotrigine is a proven analgesic in animal models of chronic pain and clinical studies of gabapentin-resistant neuropathic pain, a literature search revealed scarce data on its preemptive analgesic efficacy. Aims: The present study is designed to study the preemptive analgesic efficacy of lamotrigine in comparison with diclofenac sodium in postoperative pain control. Materials and Methods: This randomized clinical trial included 90 patients of both sexes, between 18 years and 70 years undergoing major surgeries. Patients were randomly allocated into placebo, control, and test groups and received the respective treatment 30 min before the induction of anesthesia. Aldrete score and pain score were recorded using visual analog scale (VAS), facial rating scale (FRS), and behavioral rating scale (BRS) at awakening and at 1 h, 2 h, 4 h, 6 h, and 24 h. Postoperative rescue analgesic consumption for 24 h was recorded. Results: Significantly higher pain scores were observed in the placebo group postoperatively for 2 h on all pain scales (P < 0.05), whereas in the control group it was significantly higher at 1 h (P < 0.05). The test group patients were more comfortable throughout the study and postoperative analgesic requirement was significantly less (P < 0.05). Conclusions: The study recommends the use of single oral dose lamotrigine as preemptive analgesic for effective postoperative pain control.