In theory, the use of a combination of a long-acting opioid and ketamine may be particularly efficacious in optimizing postoperative pain management. Recent evidence has demonstrated that methadone, like ketamine, has the ability to block NMDA receptors. In a neuropathic animal model, the combination of methadone and ketamine produced an analgesic synergy of a supra-additive nature. In the clinical setting, the administration of methadone and ketamine has only been examined in one small trial (20 patients). Patients randomized to receive methadone and ketamine required 70% less pain medication than those administered methadone alone. Although clinicians at NorthShore and other institutions are beginning to use methadone and ketamine in patients undergoing spinal surgery, there is limited evidence examining this approach in this patient population.