Abstract

The objective of this study was to determine the clinical efficacy of topical ketamine in relieving sympathetically maintained pain, including complex regional pain syndrome types I and II, involving the upper and/or lower extremities. In an open clinical pilot study of five referral patients diagnosed with sympathetically maintained pain who were unresponsive to conventional modalities, a single dose of topical ketamine was administered. Age, gender, duration or degree of disease and concurrent medication were not controlled. Ketamine was prepared for transdermal delivery in pluronic lethicin organogel (PLO) in calibrated applicators. Concentrations ranged from 10 to 150 mg/mL. Dosage ranged from 10 mg to 700 mg per single application. Each dosage was determined clinically based on location and surface area of involvement. Pain intensity was measured using a validated numeric analogue scale (NAS). Ketamine in PLO applied to the upper and/or lower extremities with sympathetically maintained pain resulted in significant pain reduction relative to pretreatment NAS of 65% to 100%. Initial response was within 20 seconds to three minutes, with NAS rating 15 minutes postapplication. No reported side effect occurred on patient follow-up at 24 and 48 hours. Single-dose, topical application of ketamine in PLO (patent pending) appears clinically effective in relieving sympathetically maintained pain of the extremities without apparent side effects. Further controlled studies are warranted to define patient selection, optimize dosage and validate the prominent analgesic effects obtained in this heretofore difficult- to-treat pain syndrome. This was an independent study in joint cooperation with representatives from the University of California at Irvine, Loma Linda University Medical Center and private practice.

Related Keywords

• Lecithin
• Organogel
• Pluronic

Related Categories

• DERMATOLOGY
• PAIN MANAGEMENT