A capsaicin (8%) patch in the treatment of severe persistent inguinal postherniorrhaphy pain: a randomized, double-blind, placebo-controlled trial.

Abstract

BACKGROUND:

Persistent pain after inguinal herniorrhaphy is a disabling condition with a lack of evidence-based pharmacological treatment options. This randomized placebo-controlled trial investigated the efficacy of a capsaicin 8% cutaneous patch in the treatment of severe persistent inguinal postherniorrhaphy pain.

METHODS:

Forty-six patients with persistent inguinal postherniorrhaphy pain were randomized to receive either a capsaicin 8% patch or a placebo patch. Pain intensity (Numerical Rating Scale [NRS 0-10]) was evaluated under standardized conditions (at rest, during movement, and during pressure) at baseline and at 1, 2 and 3 months after patch application. Skin punch biopsies for intraepidermal nerve fiber density (IENFD) measurements were taken at baseline and 1 month after patch application. Quantitative sensory testing was performed at baseline and at 1, 2, and 3 months after patch application. The primary outcome was comparisons of summed pain intensity differences (SPIDs) between capsaicin and placebo treatments at 1, 2 and 3 months after patch application (significance level P < 0.01).

RESULTS:

The maximum difference in SPID, between capsaicin and placebo treatments, was observed at 1 month after patch application, but the pain reduction was not significant (NRS, mean difference [95% CI]: 5.0 [0.09 to 9.9]; P = 0.046). No differences in SPID between treatments were observed at 2 and 3 months after patch application. Changes in IENFD on the pain side, from baseline to 1 month after patch application, did not differ between capsaicin and placebo treatment: 1.9 [-0.1 to 3.9] and 0.6 [-1.2 to 2.5] fibers/mm, respectively (P = 0.32). No significant changes in sensory function, sleep quality or psychological factors were associated with capsaicin patch treatment.

CONCLUSIONS:

The study did not demonstrate significant differences in pain relief between capsaicin and placebo treatment, although a trend toward pain improvement in capsaicin treated patients was observed 1 month after patch application.

TRIAL REGISTRATION:

Clinicaltrialsregister.eu 2012-001540-22 ClinicalTrials.gov NCT01699854.

• Authors: Joakim M Bischoff, Thomas K Ringsted, Marian Petersen, Claudia Sommer, Nurcan Uçeyler, Mads U Werner
• Journal: PloS one (PLoS One) Vol. 9 Issue 10 Pg. e109144 ( 2014) ISSN: 1932-6203 [Electronic] United States
• PMID: 25290151 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Capsaicin

Topics

• Adult
• Aged
• Capsaicin (administration & dosage, adverse effects)
• Female
• Hernia, Inguinal (complications)
• Humans
• Male
• Middle Aged
• Pain (etiology)
• Pain Management (methods)
• Pain Measurement
• Risk Factors
• Skin (innervation)
• Surveys and Questionnaires
• Transdermal Patch