Randomized controlled trial of pregabalin for analgesia after surgical treatment of intervertebral disc disease in dogs

Objective To assess the effect of perioperative pregabalin on pain behavior in dogs after intervertebral disc surgery. Study design Prospective, randomized, controlled clinical trial with a blinded observer. Animals Forty-six client-owned dogs undergoing intervertebral disc surgery. Methods Dogs were randomly assigned to two groups, with the placebo group receiving opioids alone and the pregabalin group receiving opioids plus pregabalin. Opioid analgesia consisted of 0.6 mg/kg l-methadone given intravenously at anesthetic induction, followed by 0.2 mg/kg given at 8, 16, and 24 hours after extubation and fentanyl patches applied at the end of surgery. Pregabalin was given orally (4 mg/kg) 1 hour before anesthesia, followed by postoperative treatment three times per day (4 mg/kg) for 5 days. The outcome measures were the treatment-group differences in peri-incisional mechanical sensitivity and Glasgow Composite Measure Pain Scale (CMPS-SF) assessed during the first 5 postoperative days. Pregabalin serum concentrations were measured after 24, 72, and 120 hours. Results Pregabalin reduced pain levels in the treatment group by a mean of 2.5 CMPS-SF units (95% confidence interval [CI] = -3.19 to -1.83, P < .001) compared with the control group during the study period. Pregabalin increased the mechanical nociceptive threshold by a mean of 6.89 N per day (95% CI = 1.87-11.92, P < .001) and of 7.52 N per day (95% CI = 2.29-12.77, P < .001) during the study period, depending on location. Mean levels of serum pregabalin were 5.1, 4.71, and 3.68 mu g/mL at 24, 72, and 120 hours postoperatively, respectively. Conclusion Postoperative signs of pain after surgical treatment of intervertebral disc herniation (IVDH) were reduced when dogs received perioperative pregabalin rather than opioids alone. Clinical significance Perioperative pregabalin reduces postoperative pain after surgical treatment of IVDH.