A randomized controlled trial to compare pregabalin with gabapentin for postoperative pain in abdominal hysterectomy

BACKGROUND Pregabalin is a potent ligand for alpha-2-delta subunit of voltage-gated calcium channels in the central nervous system, which exhibits potent anticonvulsant, analgesic and anxiolytic activity. The pharmacological activity of pregabalin is similar to that of gabapentin and shows possible advantages. Although it shows analgesic efficacy against neuropathic pain, very limited evidence supports its postoperative analgesic efficacy. We investigated its analgesic efficacy in patients experiencing acute pain after abdominal hysterectomy and compared it with gabapentin and placebo. METHODS A randomized, double-blind, placebo-controlled study was conducted in 90 women undergoing abdominal hysterectomy who were anaesthetized in a standardized fashion. Patients received 300 mg pregabalin, 900 mg gabapentin or placebo, 1-2 hours prior to surgery. Postoperative analgesia was administered at visual analogue scale (VAS) ≥3. The primary outcome was analgesic consumption over 24 hours and patients were followed for pain scores, time to rescue analgesia and side effects as secondary outcomes. RESULTS The diclofenac consumption was statistically significant between pregabalin and control groups, and gabapentin and control groups; however, pregabalin and gabapentin groups were comparable. Moreover, the consumption of tramadol was statistically significant among all the groups. Patients in pregabalin and gabapentin groups had lower pain scores in the initial hour of recovery. However, pain scores were subsequently similar in all the groups. Time to first request for analgesia was longer in pregabalin group followed by gabapentin and control groups. CONCLUSION A single dose of 300 mg pregabalin given 1-2 hours prior to surgery is superior to 900 mg gabapentin and placebo after abdominal hysterectomy. Both the drugs are better than placebo.