Preoperative gabapentin decreases anxiety and improves early functional recovery from knee surgery

Gabapentin has antihyperalgesic and anxiolytic properties. We thus tested the hypothesis that premedication with gabapentin would decrease preoperative anxiety and improve postoperative analgesia and early postoperative knee mobilization in patients undergoing arthroscopic anterior cruciate ligament repair under general anesthesia. Forty patients were randomly assigned to receive 1200 mg oral gabapentin or placebo 1-2 h before surgery; anesthesia was standardized. Patients received morphine, 0.1 mg/kg, 30 min before the end of surgery and postoperatively via a patient-controlled pump. Pain scores and morphine consumption were recorded over 48 h. Degrees of active and passive knee flexion and extension were recorded during physiotherapy on days 1 and 2. Preoperative anxiety scores were less in the gabapentin than control group (visual analog scale scores of 28 +/- 16 mm versus 66 +/- 15 mm, respectively; P < 0.001). The gabapentin group required less morphine than the control group (29 +/- 22 mg versus 69 +/- 40 mg, respectively; P < 0.001). Visual analog scale pain scores at rest and after mobilization were significantly reduced in the gabapentin group. First and maximal passive and active knee flexions at 24 and 48 h were significantly more extensive in the gabapentin than in the control group. In conclusion, premedication with 1200 mg gabapentin improved preoperative anxiolysis, postoperative analgesia, and early knee mobilization after arthroscopic anterior cruciate ligament repair.