Topical Capsaicin in the Management of HIV-Associated Peripheral Neuropathy

Abstract

Distal symmetrical peripheral neuropathy (DSPN) is a particularly distressing pain syndrome associated with human immunodeficiency virus (HIV) disease. Capsaicin has been found to be effective in relieving pain associated with other neuropathic pain syndromes, and is mentioned as a possible topical adjuvant analgesic for the relief of DSPN. This multicenter, controlled, randomized, double-masked clinical trial studied patients with HIV-associated DSPN and compared measures of pain intensity, pain relief, sensory perception, quality of life, mood, and function for patients who received topical capsaicin to the corresponding measures for patients who received the vehicle only. Twenty-six subjects were enrolled in the study. At the end of 1 week, subjects receiving capsaicin tended to report higher current pain scores than did subjects receiving the vehicle (Mann-Whitney test; P = 0.042). The dropout rate was higher for the capsaicin group (67%) than for the vehicle group (18%) (chi 2 test of association; P = 0.014). There were no other statistically significant differences between the capsaicin and vehicle groups with respect to current pain, worst pain, pain relief, sensory perception, quality of life, mood, or function at study entry or at any time during the 4-week trial. These results suggest capsaicin is ineffective in relieving pain associated with HIV-associated DSPN.

The Two Faces of Capsaicin

“…Oral capsaicin in a candy (taffy) vehicle produced substantial temporary pain reduction in 11 patients with oral mucositis pain from cancer therapy (44). However, capsaicin was not effective in relieving pain accompanying HIV-associated distal symmetrical peripheral neuropathy (45).…”

Topical capsaicin for chronic neuropathic pain in adults

“…Four studies identified (Basha 1991;Donofrio 1991;Scheffler 1991;Tandan 1992) were reports of parts of a multicentre study (CSG 1992), only one of which (Tandan 1992, 22 participants) provided any additional data. Eleven other studies were excluded after reading the full report (Chad 1990;Fusco 1992;McCarty 1994;McCleane 2000;Paice 2000;Peikert 1991;Pfeifer 1993;Robbins 1998;Vickers 1998;Watson 1988;Watson 1989). Reasons for exclusion are in the 'Characteristics of excluded studies' table.…”

“…Similarly, investigator or physician reported outcomes do not reliably correspond to patient outcomes. In particular, four studies of 4 weeks' duration were excluded (Chad 1990;McCarty 1994;McCleane 2000;Paice 2000). These studies enrolled 329 participants, 90 of whom were treated with 0.075% capsaicin, and 21 with 0.025% capsaicin.…”

Topical and Peripherally Acting Analgesics

“…Topical capsaicin is generally not considered a satisfactory sole therapy for chronic pain conditions and is often considered an adjuvant to other approaches (Watson, 1994). No significant benefit was reported in chronic distal painful neuropathy (Low et al, 1995) or with human immunodeficiency virus-neuropathy (Paice et al, 2000).…”