title: Topical Treatment of Peripheral Neuropathic Pain: Applying the Evidence.
abstract: Patients with peripheral neuropathic pain (NP) may only achieve partial pain relief with currently recommended first-line oral treatments, which are also associated with systemic adverse events. Topical treatments are currently considered second- or third-line options, but a recent pharmacologic treatment algorithm has called for broader first-line use of these agents. This has highlighted a need to communicate the benefits associated with topical agents, in particular around the efficacy, targeted local action, and limited systemic availability resulting in minimal systemic adverse events and drug-drug interactions.
  
  
  
  This review aims to evaluate the evidence base for topical therapies currently used to treat peripheral NP, discuss the evidence comparing these treatments head-to-head with oral standard of care, and evaluate how they fit into treatment regimens in the "real world."
  
  
  
  This is a narrative review.
  
  
  
  Two topical treatments are currently licensed: lidocaine 5% medicated plaster (post-herpetic neuralgia) and the capsaicin 8% patch (peripheral NP). When compared head to head with the oral standard of care (pregabalin), the lidocaine 5% medicated plaster provided similar relief of pain associated with post-herpetic neuralgia but did not meet the primary predefined criteria for noninferiority. The capsaicin 8% patch, however, demonstrated noninferior efficacy when compared head-to-head with pregabalin across a wide range of peripheral NP etiologies. Importantly, both treatments demonstrated effective pain relief without the systemic adverse events associated with oral therapies.
  
  
  
  First-line use of topical agents may be of particular benefit in patients where the safety and tolerability of oral therapy is a concern.
authors.affiliation: Neurologische Klinik, Universitätsklinikum Würzburg, Würzburg, Germany. Electronic address: sommer@uni-wuerzburg.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Sommer
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University, Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Cruccu
mesh_terms: D000287:Administration, Topical; D000700:Analgesics / Q000008:administration & dosage*; D055416:Evidence-Based Emergency Medicine; D006801:Humans; D009437:Neuralgia / Q000188:drug therapy* / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D000700:Analgesics
keywords: Peripheral neuropathic pain; capsaicin 8% patch; lidocaine 5% medicated plaster; topical