Topical Amitriptyline and Ketamine in Neuropathic Pain Syndromes: An Open-Label Study

This study demonstrates that topical 2% amitriptyline/1% ketamine, given over 6-12 months, is associated with long-term perceived analgesic effectiveness in treatment of neuropathic pain. Antidepressants and ketamine both produce multiple pharmacologic effects that may contribute to peripheral analgesia; such actions include block of peripheral N-methyl-D-aspartate receptors, local anesthetic properties, and interactions with adenosine systems.