Treatment of peripheral neuropathic pain by topical capsaicin: Impact of pre-existing pain in the QUEPP-study

Abstract

Background: This study evaluates the impact of the duration of pre-existing peripheral neuropathic pain on the therapeutic response to the capsaicin 8% cutaneous patch.

Methods: The non-interventional QUEPP (QUTENZA - safety and effectiveness in peripheral neuropathic pain) study evaluated the effectiveness of Qutenza(TM) in 1044 non-diabetic patients with peripheral neuropathic pain, who received a single application. Follow-up visits were scheduled at weeks 1-2, 4, 8 and 12. A pre-defined co-analysis of changes in average pain intensity was performed based on the duration of pre-existing pain.

Results: In patients with pre-existing pain for <6 months, the mean relative change of the numeric pain rating scale score on days 7-14 to week 12 versus baseline was -36.6% [4.6 standard error of the mean (SEM); n = 105], -25.1% (1.9 SEM; n = 311) in patients with pain duration of 6 months to 2 years, -22.3% (1.6 SEM; n = 391) in patients with pain for >2-10 years, and -19.2% (2.6 SEM; n = 99) in patients with pain for >10 years. Thirty percent and 50% responder rates were 61.7% and 39.3% in patients with pre-existing pain for <6 months, 42.3% and 23.3% in patients with pain for 6 months to 2 years, 40.9% and 21.6% in patients with pain for >2-10 years, and 32.3% and 14.1% in patients with pain for >10 years.

Conclusions: The highest treatment response to the capsaicin 8% cutaneous patch was observed in patients with a history of pre-existing peripheral neuropathic pain of less than 6 months, suggesting that early initiation of topical treatment might be indicated.

Figure 1

Time course of mean pain intensities in the subgroups of duration of pre-existing peripheral neuropathic pain (m, months; y, years, NPRS, numeric pain rating scale 0–10; **p ≤ 0.01; ***p ≤ 0.001, single t-test).

Figure 2

Mean relative changes (%) of short form-12 (SF-12) physical and mental summary scale scores between week 12 and baseline in subgroups of duration of pre-existing pain (m, months; y, years).

Figure 3

Percentage of patients with co-medication for neuropathic pain in the subgroups of pre-existing duration of pain (m, months; y, years; NP, neuropathic pain).