SLR - July 2013 - James A. Averett
Reference: Campbell CM, Kipnes MS, Stouch BC, Brady KL, Kelly M, Schmidt WK, Petersen KL, Rowbotham MC, Campbell JN. Randomized control trial of topical clonidine for treatment of painful diabetic neuropathy Pain. 2012 Sep; 153(9): 1815-23.
Scientific Literature Review
Reviewed by: James A. Averett, DPM
Residency Program: Southern Arizona VA Health Care System
Methods: This study was a randomized, double blind, placebo-controlled, parallel-group, multi-center trial. Four hundred sixty-four patients were screened and 182 were randomized into two groups. Nociceptor function was measured by determining the painfulness of 0.1 percent topical capsaicin applied to the pretibial area of each subject for 30 minutes during inspection. Subjects were then randomized to receive 0.1 percent topical clonidine gel or placebo gel applied three times a day to their feet for 12 weeks. The difference in foot pain at week 12 in relation to baseline, rated on a 0-10 numerical pain rating scale (NPRS), was compared among groups.
Results: The subjects treated with topical clonidine displayed decreased foot pain when compared to the placebo-treated group. In subjects who felt pain to capsaicin, clonidine was superior to placebo. In subjects with a capsaicin pain rating ≥2 (0-10, NPRS), the mean decrease in foot pain was 2.6 for active compared to 1.4 for placebo.Conclusions: Topical clonidine gel reduces the level of foot pain in painful diabetic neuropathy subjects with functional, and possibly sensitized, nociceptors in the affected skin as discovered by testing with topical capsaicin. Screening for nociceptor function may help differentiate candidates for topical therapy for neuropathic pain. Topical clonidine should be considered in the treatment of painful diabetic neuropathy in the podiatric setting.