A Pilot Study Examining Topical Amitriptyline, Ketamine, and a Combination of Both in the Treatment of Neuropathic Pain.

This is a pilot study providing initial information regarding the use of novel topical preparations containing amitriptyline (AMI), ketamine (KET), and a combination of both in the treatment of neuropathic pain. The study design included a 2 day randomized, double blind, placebo controlled, 4 way cross-over trial of all treatments, followed by an open label treatment phase using the combination cream for 7 days. Twenty volunteers with chronic neuropathic pain were randomly assigned to treatment order and applied 5 mis of each topical treatment (1% AMI, 0.5% KET, combination AMI 1%/KET 0.5%, and placebo) for 2 days. Measures of pain at the end of each block included the short form McGill Pain Questionnaire (MPQ) and visual analog scales (VAS) for present pain intensity and pain relief. Eleven subjects who judged subjective improvement from any treatment in the initial trial entered the open-label trial and used the combination cream for 7 days. There was no statistically significant difference from placebo after 2 days for any treatment during the double blind component of the trial. This pilot study demonstrated a lack of effect for all treatments in the 2 day double blind placebo controlled trial. (PsycInfo Database Record (c) 2021 APA, all rights reserved)