Analgesic effect of oral ketamine in chronic neuropathic pain of spinal origin: a case report.

Ketamine is an injectable anesthetic induction agent that has been reported to have analgesic activity in pain from a variety of mechanisms, but predominantly in neuralgic and dysesthetic neuropathic pain. In this case report we illustrate the effectiveness of ketamine in a patient with neuropathic pain resulting from cauda equina trauma. Among the issues addressed are the role of pretreatment with haloperidol to prevent ketamine-induced psychomimetic effects, the potential for fewer side effects and a need for lower doses when ketamine is administered orally, and the need for further study regarding appropriate monitoring parameters during the titration phase. Oral ketamine can be effective in treatment refractory chronic neuropathic pain of spinal origin.