Comparison of Efficacy of Topical Glycerin Trinitrates with Capsaicin in Painful Diabetic Neuropathy

Abstract

Objective: To compare the efficacy of topical glycerin trinitrates with capsaicin in painful diabetic
peripheral neuropathy.
Material & Methods: This quasi experimental study was conducted in Diabetes Management
Centre Medical Unit-IV Services Hospital, Lahore over a period of six months from 01-06-2008 to
30-11-2008. Sixty-two patients of diabetes mellitus having symptoms of neuropathy were included
in this study and were divided into two groups of thirty one patients each. In group A topical
capsaicin cream was applied twice a day for thirty minutes for the period of seven days at the
strength of 0.075% w/w. In group B glycerin trinitrate cream was applied twice a day for thirty
minutes for the period of seven days at the strength of 2% w/w. After seven days of treatment,
intensity of numbness and paraesthesia and tissue perfusion were again assessed using visual
analogue scale and periscan respectively. Periscan and visual analogue chart assessment were
repeated after the seven days wash out period and patients were crossed over to the other
treatment group. Numbness and paraesthesia were reassessed at the end of last treatment on
visual analogue chart and periscan were repeated as well for tissue perfusion.
Results: The age of the patients in group Awas 49.90±8.06 years and in group B was 49.58±6.62
years. In group A, the efficacy of GTN in peripheral neuropathy was 38.7% as compared to
capsacin which was only 19.3%. Similar results were seen in group B, in which efficacy of GTN in
peripheral neuropathy was 51.6% as compared to capsaicin that was 29%.The overall results
when combined in both the groups showed a response to capsaicin in 15 (24.2%) patients only
versus 28 (45.2%) to GTN. This difference was statistically significant (p=0.02356).
Conclusion: There is a significant difference in efficacy of topical glycerin trinitrates and
capsaicin in the management of diabetic peripheral neuropathy. GTN cream, a well-tolerated
drug, provides significant improvement in painful diabetic neuropathy