Placebo Response in Neuropathic Pain Trials!
Both placebo and nocebo effects can greatly affect the interpretation of outcomes in randomized controlled trials of chronic neuropathic pain treatments. When trials are being designed and interpreted, these effects need to be considered so that safety and efficacy can be better determined. Clinicians who are trying to determine causality vs association between an event and a medication when treating chronic neuropathic pain need to know if outcomes are related to a placebo or nocebo effect. For future trials, the best choice of endpoints when studying chronic neuropathic pain may be determined by this study's findings.
@dilnaj This was a systematic review and meta-analysis of randomized controlled trials in which drugs (topical capsaicin, tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, calcium channel alpha-2-delta ligands) used to treat chronic peripheral neuropathic pain were compared with placebo. The trials studied individuals 18 years of age or older with chronic peripheral neuropathic pain in the following categories: chemotherapy-induced peripheral neuropathy, HIV neuropathy, painful diabetic peripheral neuropathy, postherpetic neuralgia, mixed disease, and postsurgical neuropathy. The primary endpoints were placebo response (proportion of patients with reported pain intensity reduction ≥30% in the placebo arm) and nocebo response (proportion of patients with adverse events).