Ketamine is not a new drug. It is an anesthetic drug that has been used for decades in human and veterinarian medicine since it was introduced into clinical practice in 1970. When used in anesthetic doses it produces a complete loss of consciousness while retaining certain protective reflexes. This has made it an attractive choice for anesthesiologists in selective patients. Although it does stimulate opiate receptors, much like morphine, its NMDA receptor antagonism at subanesthetic doses is believed to be much more important in the treatment for chronic pain or psychiatric disorders. It blocks the NMDA receptor and prevents the passage of ions through the channel which interrupts pain signal transduction, giving the central pain center a chance to “reboot”. Often, this means the patient must undergo a series of low dose ketamine infusions for amazing relief or complete elimination of chronic pain. Ketamine Infusions are often used when other treatment modalities have failed. Specific types of pain that are considered “neuropathic” in origin have been studied the most and considered to be the most responsive to ketamine therapy.