The analgesic property of capsaicin has been clinically investigated for the treatment of a number of disorders, including complex regional pain syndromes and neuropathic pain; postsurgical neuropathic pain; post-herpetic neuralgia; painful diabetic peripheral neuropathy; and cannabinoid hyperemesis syndrome (CHS). There is also evidence that repeated use of nasal capsaicin prevents cluster headache attacks.
Two review papers that summarize current research are:
- V. Fattori et al., “Capsaicin: Current Understanding of Its Mechanisms and Therapy of Pain and Other Pre-Clinical and Clinical Uses”, Molecules, Vol 21, No 844, 2016.
- S. Basith et al., “Harnessing the Therapeutic Potential of Capsaicin and Its Analogues in Pain and Other Disease”, Molecules, Vol 21, No 966, 2016.
What follows are other papers presenting clinical data for externally applied capsaicin in the treatment of specific disorders.
- Data from placebo–controlled trials show that topical capsaicin treatment four times daily is moderately effective in reducing pain intensity over 12 weeks and possibly longer.
[L.L. Laslett and G. Jones, “Capsaicin for Osteoarthritis Pain”, Capsaicin as a Therapeutic Molecule, Ch 11, Springer Basel, 2014.]
- Topical capsaicin cream administered QID (4 times a day) is a safe and effective adjunctive therapy for patients with OA pain.
[T. Schnitzer et al., “Topical capsaicin therapy for osteoarthritic pain: achieving a maintenance regimen”, Seminars in Arthritis and Rheumatism, Vol 23, No 6, Sup 3, June 1974, pp 34-40.]
- Current evidence indicates that topical NSAIDs and capsaicin offer similar levels of pain relief in OA.
[M.S.M. Persson et al., “The relative efficacy of topical non-steroidal anti-inflammatory drugs and capsaicin in osteoarthritis: a network meta-analysis of randomised controlled trials”, Osteoarthritis and Cartilage, Vol 26, Issue 12, December 2018, pp 1575-1582.]
- With its high analgesic efficacy and absence of systemic side effects, topical capsaicin can be used safely in patients presenting to the emergency department with acute pain.
[S.T.A. Gur et al, “Topical capsaicin versus topical ibuprofen in acute musculoskeletal injuries: A randomized, double-blind trial”, Hong Kong Journal of Emergency Medicine, December 2020.]
- Postherpetic neuralgia is an important cause of morbidity, particularly in older persons, and is notoriously resistant to treatment. The results of this study suggest that topically applied capsaicin is a safe and effective treatment for this condition.
[J.E. Bernstein et al., “Topical capsaicin treatment of chronic postherpetic neuralgia”, Journal of the American Academy of Dermatology, Vol 21, No 2, Part 1, August 1989, pp 265-270.]
Cannabinoid Hyperemesis Syndrome (CHS)
- Significantly more patients in the capsaicin group experienced efficacy compared to patients who did not. Time to discharge after administration of the reference agent was shorter for those who received capsaicin compared to patients who did not.
[V. Kum et al., “Efficacy of topical capsaicin for cannabinoid hyperemesis syndrome in a pediatric and adult emergency department”, American Journal of Emergency Medicine, Vol 49, November 2021, pp 343-351.]
- There was no significant difference in ED LOS (Emergency Department Length of Stay) when capsaicin was utilized for CHS. However, there was a decrease in total medications administered and a reduction in opioid requirements. While medication costs for capsaicin visits were minimally more expensive, the utility of capsaicin as an over-the-counter (OTC) product may empower at home therapy with OTC products, decreasing potentially unnecessary healthcare encounters and costs.
[S. Wagner et al., “Efficacy and safety of topical capsaicin for cannabinoid hyperemesis syndrome in the emergency department”, Clinical Toxicology, Vol 58, No 6, 2020, pp 471-475.]