New antidepressants in the treatment of neuropathic pain: A review

Before 1980s, tricyclics (TCAs) were considered, between antidepressants, the standard in the treatment of different kinds of neuropathic pain, for their action on noradrenergic and serotoninergic pathways, thought the high incidence of side effects. In 1980s a new class of antidepressants has been introduced, the selective serotonin reuptake inhibitors (SSRI). We reviewed some publications, including trials comparing SSRIs with TCAs in pain management. The available literature did not show an effective superiority of the former on the latter, though improved side-effect profile. Recently new antidepressants were introduced in the clinical use, with a significant reduction in side effects and equivalent efficacy on mood disorders. These new drugs may be classified in three categories: Serotonin and Noradrenergic Reuptake Inhibitors (SNaRI), like venlafaxine and nefazodone; Noradrenergic and Specific Serotoninergic Antidepressants (NaSSA), like mirtazapinc, and Noradrenaline Reuptake Inhibitors (NaRI), like reboxetine. In this review we present the available publications of their application in the treatment of neuropathic pain. Venlafaxine (SNaRI), the most investigated of these new drugs, was shown to be effective in the treatment of different kinds of pain, with side-effects profile significantly better than TCAs. The other new antidepressants have been less extensively studied, thus only anecdotal therapeutic results and experimental works have been found and reported. Existing data are surely insufficient to conclude which of these new classes of drugs has the best clinical profile and can be more effective in the treatment of neuropathic pain, but the lower incidence of side effects should be considered. Further evidence-based research in the safety and efficacy of these promising agents in pain relief, is warranted.