Effect of Treatment With Capsaicin on Daily Activities of Patients With Painful Diabetic Neuropathy

Abstract

OBJECTIVE-To establish the effects of topically applied capsaicin on daily activities in patients with painful diabetic neuropathy. RESEARCH DESIGN AND METHODS-Investigators at 12 sites enrolled 277 men and women with painful peripheral polyneuropathy and/or radiculopathy in an 8-wk double-blind vehicle-controlled study with parallel randomized treatment assignments. Participants were unresponsive or intolerant to conventional therapy and were experiencing pain that interfered with functional activities and/or sleep. Either 0.075% capsaicin cream or vehicle cream was applied to the painful areas 4 times/day. A visual analogue scale of pain intensity and baseline measurements of the pain's interference with the ability to walk, work, participate in recreational activities, use shoes and socks, sleep, and eat were recorded at onset and at 2-wk intervals. A physician's global evaluation scale assessed changes in pain status from baseline. RESULTS-Statistically significant differences are percentage of patients with improvement in favor of capsaicin versus vehicle: 69.5 vs. 53.4% with clinical improvement in pain status (P = 0.012), 26.1 vs. 14.6% with improvement in walking (P = 0.029), 18.3 vs. 9.2% with improvement in working (P = 0.019), 29.5 vs. 20.3% with improvement in sleeping (P = 0.036), and 22.8 vs. 12.1% with improvement in participating in recreational activities (P = 0.037). CONCLUSIONS-The results from this study suggest that topical 0.075% capsaicin is effective for reducing pain in patients with painful diabetic neuropathy with subsequent improvement in daily activities, enhancing the quality of the patient's life.

Current Pharmacological Treatment of Painful Diabetic Neuropathy: A Narrative Review

“…Two forms of capsaicin are available for the treatment of painful DSPN: a low-dose cream (0.075%) [31] and a high-dose (8%) patch (Qutenza, Acorda Therapeutics, Ardsley, NY, USA) [56]. A series of studies have provided evidence of pain relief among subjects who received capsaicin cream in comparison to the vehicle [57][58][59][60], although results were inconsistent [61][62][63]. An older study even provided evidence of equal efficacy of capsaicin cream (0.075%) to oral amitriptyline for painful DSPN [64].…”

Topical treatments for diabetic neuropathic pain (Review)

“…The Capsaicin Study Group attempted to define the efficacy and safety of topical 0.075% capsaicin in patients with painful diabetic neuropathy. Improvement in pain relief, pain intensity and daily activities, including sleeping, walking and the ability to work and participate in recreational activities, were observed in significantly more patients treated with capsaicin than with a vehicle (69,70). Compared with oral amitriptyline, topical 0.075% capsaicin cream was equally effective but considerably safer according to the results of a comparative study in patients with painful diabetic neuropathy (71).…”

A Systematic Guideline by the ASPN Workgroup on the Evidence, Education, and Treatment Algorithm for Painful Diabetic Neuropathy: SWEET

“…50 As a TRPV1 agonist, capsaicin initially causes depolarization and action potential propagation, which desensitizes the nociceptive fibers, triggering sensations of warmth, itching, or pain. [50][51][52] This chemical cascade is associated with a marked increase of intracellular calcium, and sustained capsaicin exposure in high doses results in "defunctionalization", or reversible ablation of the nociceptive fibers, characterized by loss of cell membrane potential, receptor desensitization, substance P depletion, and reduced nerve fiber density, thus decreasing pain signals sent to the brain. 50 Additionally, capsaicin-activated TRPV1 in immune cells can mitigate inflammation, further contributing to its analgesic and potential anti-inflammatory effects.…”