title: Use of the lidocaine patch 5% in reducing intensity of various pain qualities reported by patients with low-back pain.
abstract: OBJECTIVE
  To determine the impact of the lidocaine patch 5% on pain qualities associated with low-back pain (LBP) through use of the Neuropathic Pain Scale (NPS).
  
  
  METHODS
  Patients were enrolled in an open-label, non-randomized, prospective, 6-week study involving 8 clinical trial sites in the United States. Eligible patients had non-radicular LBP and reported moderate-to-severe pain on the NPS at study enrollment. Patients were stratified to 3 groups based on the duration of their LBP, defined as acute/sub-acute (< 3 months), short-term chronic (3-12 months), or long-term chronic LBP (> 12 months). The lidocaine patch 5% was applied to the area of maximal pain, using no more than a total of 4 patches changed every 24 h. Effectiveness was measured by change from baseline to Week 2 and Week 6 in 4 composite measures of the NPS: NPS-10, NPS-4, NPS-8, and NPS-non-allodynia. Safety was assessed by adverse events (AEs), dermal assessment of application site(s), and skin sensory testing.
  
  
  RESULTS
  In the combined patient population (n = 71), 6 weeks of treatment with lidocaine patch 5% significantly improved all 4 NPS composite measures at both Week 2 and Week 6 (p < 0.001). Separate analyses by subgroups revealed differential improvements in the 4 composite measures. Eleven patients (15.5%) experienced treatment-related AEs that were primarily mild-to-moderate and dermal in nature.
  
  
  CONCLUSIONS
  In patients with moderate-to-severe LBP, 2 weeks and 6 weeks of treatment with the lidocaine patch 5% significantly reduces the intensity of pain qualities as measured by all 4 NPS composite measures. Lidocaine patch 5% is well tolerated with few systemic AEs and may provide beneficial pain relief for patients receiving multidisciplinary treatment without increasing risks for adverse drug interactions. Pain scales such as the NPS offer the ability to measure various pain qualities experienced by LBP patients and may allow clinicians to assess the treatment impact of different medications.
authors.affiliation: Endo Pharmaceuticals, Inc, Chadds Ford, PA 19317, USA. Galer.Bradley@Endo.com
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Galer
authors.forename: Arnold R
authors.initials: AR
authors.lastname: Gammaitoni
authors.forename: Napoleon
authors.initials: N
authors.lastname: Oleka
authors.forename: Mark P
authors.initials: MP
authors.lastname: Jensen
authors.forename: Charles E
authors.initials: CE
authors.lastname: Argoff
mesh_terms: D000279:Administration, Cutaneous; D000779:Anesthetics, Local / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods*; D010865:Pilot Projects; D011446:Prospective Studies; D016896:Treatment Outcome; D014481:United States
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine