title: Metformin: Potential analgesic?
abstract: OBJECTIVE
  To determine the association of self-report use of metformin and pain intensity.
  
  
  METHODS
  Survey-based cross sectional.
  
  
  METHODS
  Primary care in an academic medical center.
  
  
  METHODS
  Three hundred and twenty nine participants with diabetes.
  
  
  METHODS
  A total of 329 men and women, aged 18-65, completed a phone-based survey. We utilized the Brief Pain Inventory to assess for pain intensity ratings; Leeds Assessment of Neuropathic Symptoms and Signs to screen for neuropathy; and the Personal Health Questionnaire (PHQ8) Depression Scale to assess for depression.
  
  
  RESULTS
  Three hundred and twenty nine diabetics (mean age 54- ± 8-year old) completed the study (162 metformin users, 167 nonusers). Compared with non-users, metformin users were used more often [38% vs 20%, P = 0.001]; had lower mean depression scores [6.8 vs 8.3; P = 0.026] and fewer comorbidities [1.5 vs 1.8, P = 0.022]. Adjusting for those three variables, pain scores were not significantly different between groups. In a subset analyses of those with neuropathic pain (n = 156), there were no differences in pain scores found between groups.
  
  
  CONCLUSIONS
  In a clinic sample of patients with diabetes, the use of metformin at an average dose of 1,432 mg (SD = 596 mg) was not associated with lower pain scores. Given the anti-nociceptive effects of metformin in the animal models of pain, and the relative safety of metformin, future research should evaluate the effect of the higher dose of metformin as a potential analgesic.
authors.affiliation: Section on Rheumatology and Immunology, Wake Forest University School of Medicine, Medical Center Blvd, 3rd Floor, Watlington Hall, Winston Salem, North Carolina, USA.
authors.forename: Brett
authors.initials: B
authors.lastname: Smith
authors.affiliation: Section on Rheumatology and Immunology, Wake Forest University School of Medicine, Medical Center Blvd, 3rd Floor, Watlington Hall, Winston Salem, North Carolina, USA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Ang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000700:Analgesics / Q000008:administration & dosage; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D008297:Male; D008687:Metformin / Q000008:administration & dosage*; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*; D056687:Off-Label Use; D010147:Pain Measurement / Q000187:drug effects*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000700:Analgesics; D007004:Hypoglycemic Agents; D008687:Metformin
keywords: Diabetic Neuropathy; Neuropathic Pain; Neuropathy; Pain Management; Pain Medicine