Novel treatment using ketamine has shown success in reducing the severe pain caused by Complex Regional Pain Syndrome

A novel treatment using a common anesthetic drug has shown success in reducing the severe pain caused by Complex Regional Pain Syndrome (CRPS), according to a study published in the September 2004 issue of Pain Medicine.

CRPS, a disorder that can be associated with chronic pain resistant to conventional therapies, affects between 1.5 and 7 million people in the United States. CRPS is sometimes also known as Reflex Sympathetic Dystrophy (RSD).

“This pain disorder can be very difficult to treat. Currently-available conventional therapies, at best, oftentimes only make the pain bearable for many CRPS sufferers,” said Ronald E. Harbut, MD, PhD, of Penn State Milton S. Hershey Medical Center, corresponding author of the study. “In our retrospective study, some patients who underwent a low-dose infusion of ketamine experienced complete relief from their pain, suggesting that this therapy may be an option for some patients with intolerable CRPS.”

Thirty-three patients with unrelenting CRPS were treated using this novel approach developed by Dr. Graeme E. Correll, BE, MBBS, in Mackay, Queensland, Australia. Pain relief and the duration of this relief appeared impressive. After only one treatment, there was complete relief in 76% (25) of the group. 54% of the patients remained free of pain for more than three months, 31% for more than six months. Although the relief of pain did not last indefinitely, it was noted that following a second treatment given to 12 of the patients, the outcome was improved. In this retreated group 58% remained pain free for more than a year and almost 33% experienced relief for over three years. The most frequent side effect was a feeling of inebriation with less frequent effects including hallucinations, dizziness, light-headedness and nausea.

“Ultimately, we want to find a way to improve the quality of life for those who suffer with intolerable and endless CRPS -- that is our hope,” said Harbut. Although optimistic about these early findings, “Certainly more study is needed to further establish the safety and efficacy of this novel approach.” (A large clinical study is currently planned and under development at Penn State Hershey Medical Center.)

Rollin M. Gallagher, MD, MPH, Editor-in-Chief of Pain Medicine, notes, “How medical breakthroughs occur is usually a story of human ingenuity and perseverance fueled by compassion and intellect. Dr. Correll’s promising innovation, forged by necessity in tiny resource-poor clinics in the jungles of Papua-New Guinea and Northern Australia and carefully shepherded to publication by his co-authors, may herald an effective treatment for one of mankind’s most enigmatic and agonizing diseases. Prospective, controlled studies must follow to establish its safety and efficacy.”