Diabetic peripheral neuropathy (DPN) occurs when ongoing metabolic imbalances from diabetes damage sensory nerves and supporting blood vessels. This reduces nerve fiber density in the skin, and the remaining fibers become more sensitive due to structural and functional changes. Together with changes in local blood flow, these effects may result in patients experiencing pain, loss of normal sensation, and slower wound healing, particularly in the feet.
The capsaicin 8% topical system (referred to here as a high-concentration capsaicin topical system, or HCCTS) contains capsaicin, targets transient receptor potential vanilloid subtype 1 (TRPV1), a receptor found on certain pain-sensing nerve fibers.
Activation of TRPV1 causes an influx of calcium ions into nerve cells, triggering processes that result in the trimming of nerve fibers, or neurolysis. Trimming of nerve fibers may result in temporarily suspended pain signaling.
Over time, nerve fibers may regrow with increased density, reduced hyperexcitability, and improved blood flow responses in the skin. However, the ongoing metabolic and microvascular changes associated with diabetes can continue to cause nerve fiber dysfunction resulting in pain. HCCTS treatment may support cycles of neurolysis and nerve regrowth.
Limitations:
Further research is needed to better understand nerve damage in type 1 and type 2 diabetes and to determine when capsaicin-based therapy may be most effective, potentially at earlier disease stages. Additional studies should further characterize biologic and clinical effects of repeated treatment beyond pain relief, including potential effects on nerve damage progression and functional outcomes.