Comparison of Gabapentin v/s Pregabalin for Pre-emptive Analgesia for Acute Postoperative Pain after Surgery under Spinal Anaesthesia

Background: The objective is to evaluate the comparability of gabapentin versus pregabalin regarding the effect and safety of their use as pre-emptive analgesic for acute postoperative pain after spinal anaesthesia surgery. Material and Methods: The prospective randomized comparative study of 60 patients who underwent surgical intervention under spinal anaesthesia was designed. We randomly divided patients into two groups of 30 patients in each group. In Group G, patients were preoperatively given gabapentin and in Group P, patients were preoperatively given pregabalin. Pain assessment postpartum was done in Numeric Rating Scale at scheduled times throughout the 24-hour period following surgery. The time of first rescue analgesia, rescue analgesia consumption, number of rescue doses (if any) and adverse effects were documented and analysed between groups. Results: Basse line demographics between the two groups were similar. Patients taking pregabalin had reduced postsurgical pain scores during majority of the measurement periods. First rescue analgesia was significantly later in the pregabalin group compared to the gabapentin group (8.1 ± 1.6 hours vs. 6.2 ± 1.4 hours; p < 0.001). Total rescue analgesic consumption was also significantly lower with pregabalin (108.3 ± 31.4 vs. 142.5 ± 38.6 mg; p < 0.001). The mean number of rescue doses was lower in the pregabalin group (1.6 ± 0.6 vs. 2.1 ± 0.7; p = 0.006). There were a few more of these types of adverse effects reported in the pregabalin group, as well as a higher number of dizziness and sedation, although the differences were not statistically significant (p = 0.432). Conclusion: As compared to gabapentin, pregabalin offered the patient pre-emptive analgesia that resulted in lower postoperative pain scores and a longer duration of analgesic effect and lesser requirement for rescue analgesia. The safety profile of both drugs was acceptable. For those who have surgery with spinal anaesthetic, pregabalin might therefore be a valuable part of multimodal anaesthetic for patients.

Keywords: Gabapentin; Pregabalin; Pre-emptive analgesia; Postoperative pain; Spinal anaesthesia; Rescue analgesia.