Capsaicin dermal patch: in non-diabetic peripheral neuropathic pain

Area of Science:

• Pharmacology
• Neurology
• Dermatology

Background:

• Neuropathic pain, including postherpetic neuralgia (PHN) and HIV-associated neuropathy, presents a significant clinical challenge.
• Current treatment options for neuropathic pain have limitations in efficacy and tolerability.

Purpose of the Study:

• To evaluate the efficacy and safety of the capsaicin dermal patch for treating peripheral neuropathic pain.
• To assess the effectiveness of different application durations (30, 60, and 90 minutes) of the capsaicin dermal patch.

Main Methods:

• Pivotal, randomized, double-blind, multicentre trials were conducted in adult patients with PHN and HIV-associated neuropathy.
• Patients received a single application of high-concentration (8% w/w) capsaicin dermal patch or a low-concentration (0.04% w/w) control patch.
• Pain reduction was measured using the Numeric Pain Rating Scale (NPRS) at various time points post-application.

Main Results:

• A single 60-minute application of the capsaicin dermal patch significantly reduced NPRS scores in patients with PHN compared to the control patch.
• In HIV-associated neuropathy, 30- and 90-minute applications showed significant pain reduction, while the 60-minute application did not reach statistical significance in one study.
• An integrated analysis confirmed the 30-minute application's superiority over control for reducing NPRS scores in HIV-associated neuropathy.
• Efficacy was maintained for up to one year with repeat treatments.

Conclusions:

• The capsaicin dermal patch is an effective treatment for peripheral neuropathic pain, including PHN and HIV-associated neuropathy.
• The patch demonstrates a favorable safety profile, with transient, mild-to-moderate application-site reactions being the most common adverse events.
• The capsaicin dermal patch offers a valuable therapeutic option for managing neuropathic pain, with sustained efficacy and good tolerability.