title: A single-center randomized controlled trial of local methylcobalamin injection for subacute herpetic neuralgia.
abstract: OBJECTIVE
  This study explored the efficacy of local methylcobalamin injection in relieving pain and improving the quality of life among subjects with subacute herpetic neuralgia.
  
  
  METHODS
  A single-center, randomized controlled trial of local methylcobalamin injection was performed.
  
  
  METHODS
  Ninety-eight subjects (age, ≥ 50 years) with unilateral, dermatomal pain ≥ 4 related to herpes zoster on the torso lasting for 30 days after onset of rash were enrolled.
  
  
  METHODS
  Subjects were randomized to receive local methylcobalamin injection (N = 33), oral methylcobalamin (N = 33), or subcutaneous 1.0% lidocaine injection (N = 32) for 4 weeks. Worst pain severity, global impression of change, continuous spontaneous pain, paroxysmal pain, allodynia, paresthesia, interference with activities of daily living, and quality of life were assessed after 28-day treatment period.
  
  
  RESULTS
  Time per group interaction and group difference on overall pain at each follow-up point were statistically significant (P < 0.001) among groups. In the injected methylcobalamin group, the overall pain (P < 0.001), continuous spontaneous pain (P < 0.05), paroxysmal pain (P < 0.05), and allodynia (P < 0.05) revealed a significant effect at each follow-up point as compared with the other groups. Twenty subjects achieved pain reduction ≥ 50%, 24 perceived worst pain ≤ 3, 24 stopped using analgesics at end point; activities of daily living and quality of life improved significantly as compared with the other groups (P < 0.001). Although both of the other groups showed a significant response after the 14-day treatment (P < 0.001) compared with the baseline, oral methylcobalamin did not provide any significantly pain relief (P > 0.05).
  
  
  CONCLUSIONS
  Local methylcobalamin injection was not only efficacious in relieving pain, but also appears to be tolerable and a potential choice of treatment for subacute herpetic neuralgia.
authors.affiliation: Department of Rehabilitation Medicine, Affiliated Tenth People's Hospital of Tongji University, Shanghai, China. shiter@yeah.net
authors.forename: Gang
authors.initials: G
authors.lastname: Xu
authors.forename: Zhong-Wei
authors.initials: ZW
authors.lastname: Lv
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Wei-Zhen
authors.initials: WZ
authors.lastname: Tang
authors.forename: Gang Xiao
authors.initials: GX
authors.lastname: Xu
mesh_terms: D000368:Aged; D002681:China / Q000453:epidemiology; D015897:Comorbidity; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D051474:Neuralgia, Postherpetic / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D010147:Pain Measurement / Q000187:drug effects* / Q000706:statistics & numerical data*; D015995:Prevalence; D011788:Quality of Life; D012307:Risk Factors; D016896:Treatment Outcome; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: C019476:mecobalamin; D014805:Vitamin B 12