Gabapentin is a structural analog of gamma-amino butyric acid, and has been used as an anti-convulsant and anti-nociceptive drug. It is not metabolized in humans (therefore no hepatic enzyme induction), and is eliminated from the body by renal clearance. In animal studies, gabapentin has been demonstrated to be effective in reducing both allodynia and hyperalgesia, and may have selective effect on the nociceptive process involved in central sensitization. Gabapentin has been successfully used in the treatment of neuropathic pain and other painful conditions. Recently, there is substantial evidence to suggest that gabapentin also may be useful in the treatment of postoperative pain. To date, there have been nine randomized clinical trials of gabapentin versus placebo including a total of over 700 patients. Taken together, these studies reported that gabapentin given perioperatively significantly reduced postoperative analgesic requirements, and had minimum side effects. The only reported significant side effects in these trials were mild sedation in two studies. In patients with epilepsy, gabapentin can be introduced at therapeutic doses, and presents no safety or serious side effect issues. Since gabapentin has negligible protein binding, it has no interactions with other medications. It is recommended that metabolic and laboratory monitoring is not necessary, and excellent cognitive profile is evident. At UCSF, gabapentin has been used safely in a relatively large number of patients on an empiric bases in the postoperative period, typically in surgical patients with substantial chronic pain, and more recently, in patients who have undergone spinal surgery as an adjuvant agent to narcotics to relieve postoperative radicular pain (personal communication with Peter Koo, Clinical Pharmacist at UCSF). Typically, patients are started on gabapentin 300 mg po TID on the first day, rapidly escalating to 600 mg TID on the second day, and finally to 900 mg TID the third day until discharge. The UCSF experience suggests that gabapentin is well tolerated with minimal side effects.