title: A comparison of the lidocaine patch 5% vs naproxen 500 mg twice daily for the relief of pain associated with carpal tunnel syndrome: a 6-week, randomized, parallel-group study.
abstract: OBJECTIVE
  Carpal tunnel syndrome (CTS) is a common entrapment neuropathy caused by median nerve compression. This pilot clinical trial was designed to compare the safety and effectiveness of the lidocaine patch 5% to that of naproxen 500 mg twice daily for the treatment of neuropathic pain associated with CTS.
  
  
  METHODS
  In this 6-week, randomized, parallel-group, open-label, multicenter study, participants from 2 practice sites, aged 18 to 75 years with clinical/electrodiagnostic evidence of CTS, were randomized to receive up to 3 lidocaine 5% patches every 24 hours or naproxen 500 mg twice daily for 6 weeks. Outcome assessments included mean changes between baseline and Week 6 average pain intensity (Brief Pain Inventory [BPI]: Question 5, Average Pain Intensity [API]), an Investigator Clinical Global Impression of Improvement (CGI-I) over the course of the treatment period and a comparison of patient satisfaction (Clinical Global Assessment of Treatment [CGAT]).
  
  
  RESULTS
  One hundred patients were randomized in this study, 52 in the lidocaine patch 5% group and 48 in the naproxen 500 mg twice daily group. Significant reductions in API scores were observed between baseline and Week 6 for both lidocaine patch 5% (P < .0001) and naproxen 500 mg twice daily (P = .0004); however, there were no statistically significant differences between treatments (P = .083). There was a significant (P = .016) difference in the CGI-I for lidocaine patch 5% (51.1%) compared with naproxen 500 mg twice daily (24.3%). Whereas 71.8% of the lidocaine patch 5% patients reported being "satisfied" to "very satisfied" with the treatment, only 63.2% of naproxen 500 mg twice daily patients reported likewise, although the difference was not statistically significant. Both treatments were well tolerated. Two patients reported treatment-related adverse events in the lidocaine patch 5% group and 6 in the naproxen 500 mg twice daily group, all of which were considered mild or moderate in severity.
  
  
  CONCLUSIONS
  This study demonstrates that the lidocaine patch 5% is effective in significantly relieving the pain associated with CTS and is well tolerated. The patch may offer patients an effective, nonsystemic, noninvasive treatment for the management of their symptoms. Further controlled studies are warranted.
authors.affiliation: Kansas City University of Medicine and Biosciences, Kansas City, Missouri, USA. nalamachu@sbcglobal.net
authors.forename: Srinivas
authors.initials: S
authors.lastname: Nalamachu
authors.forename: R S
authors.initials: RS
authors.lastname: Crockett
authors.forename: Arnold R
authors.initials: AR
authors.lastname: Gammaitoni
authors.forename: Errol M
authors.initials: EM
authors.lastname: Gould
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000627:therapeutic use; D002349:Carpal Tunnel Syndrome / Q000188:drug therapy*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009288:Naproxen / Q000008:administration & dosage* / Q000627:therapeutic use; D010166:Palliative Care; D010865:Pilot Projects; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D000894:Anti-Inflammatory Agents, Non-Steroidal; D009288:Naproxen; D008012:Lidocaine