A highly concentrated 8% capsaicin patch is both effective and well tolerated as a treatment option for diabetic peripheral nerve pain (DPNP), either alone or in combination with standard oral therapies. This emerges from an overview published in the Expert Review of Neurotherapeutics. 1
Approximately half of all adults with diabetes have diabetic peripheral neuropathy. About 25% of these adults suffer from DPNP, which severely affects quality of life and is a major cause of morbidity.
There is currently no approved treatment that can reverse or prevent the progression of DPN disease. Current pharmacological management of DPN pain is focused on glycemic control and symptomatic therapies and includes α-2-δ ligands, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors.
Topical treatment modalities for DPNP include low-dose capsaicin creams (0.025% -0.075%). These creams have shown moderate effectiveness, but are often poorly tolerated due to frequent re-use and burning sensation at the application site.
The US Food and Drug Administration approved the highly concentrated 8% capsaicin patch in 2009 for post-therapeutic neuralgia and in 2020 for DPNP. Prior to approval, the development should achieve prolonged treatment efficacy through a single highly concentrated application.
The researchers conducted several clinical studies to address concerns about the systemic absorption of capsaicin. Several study protocols identified a low rate of absorption and a half-life of approximately 1.64 hours.
Researchers also investigated the therapeutic benefits of capsaicin 8% in several patient populations, including those with DPNP, HIV-associated neuropathy, post-therapeutic neuralgia, and chemotherapy-induced peripheral neuropathy. One of these studies – the Phase 3 randomized, double-blind, placebo-controlled, multicenter STEP study – included 186 patients with DPNP who received 8% capsaicin and 183 who did not. 2 Researchers found a statistically significant decrease in the primary study endpoint (percent change in mean daily pain score) from baseline to weeks 2 through 8 in the treatment group (mean percent change: -27.4 ± 26.79% versus -20.9 ± 28.92%; P = 0.025).
Although the STEP study demonstrated both clinical efficacy and tolerability, the PACE study demonstrated longitudinal efficacy, safety, and tolerability over a much longer 52-week follow-up period. 3 In this open-label, randomized, controlled, multicenter study, patients were assigned 30- or 60-minute capsaicin 8% applications plus standard of care or standard of care alone. Researchers found similar dropout rates across all study groups, and the efficacy data showed increased DPNP relief with capsaicin by 8% compared to standard treatment alone.
“The sustained pain relief after applying the patch, as well as the favorable adverse event, tolerability and systemic side effect profile make the Capsaicin 8% Patch a powerful tool that helps patients and doctors in the management of pain in diabetic nerves,” they concluded Study authors. “After monitoring, studies on the safety and tolerability of the Capsaicin 8% Patch in patients with DPNP will likely be in preparation.”
Disclosure: Several authors of the study have stated that they are part of the pharmaceutical industry. For a full list of the authors’ information, see the original reference.
- Abrams RMC, Pedowitz EJ, Simpson DM. A Critical Review of the Capsaicin 8% Patch for the Treatment of Neuropathic Pain Associated with Diabetic Peripheral Neuropathy of the Feet in Adults. Expert Rev Neurother. Published online January 11, 2021. doi: 10.1080 / 14737175.2021.1874920
- Simpson DM, Robinson-Papp J., Van J. et al. Capsaicin 8% patch in painful diabetic peripheral neuropathy: a randomized, double-blind, placebo-controlled study. J pain. 2017; 18 (1): 42-53.
- Vinik AI, Perrot S., Vinik EJ et al. Capsaicin 8% Patch Repeat Treatment Plus Standard of Care (SOC) versus SOC alone for painful diabetic peripheral neuropathy: a randomized, 52-week, open-label safety study. BMC Neurol. 2016; 16 (1): 251.
This article originally appeared on Clinical Pain Advisor