title: Analgesic efficacy and tolerability of flupirtine vs. tramadol in patients with subacute low back pain: a double-blind multicentre trial*.
abstract: OBJECTIVE
  To assess the efficacy and tolerability of flupirtine in comparison with tramadol for the treatment of moderate to severe subacute low back pain (LBP).
  
  
  METHODS
  In this randomised, double-blind, parallel-group trial, 209 LBP patients, aged 18-65 years, were orally treated with flupirtine 100 mg (n = 105) vs. tramadol 50 mg (n = 104), both three times daily for 5-7 days.
  
  
  METHODS
  Patient assessment of pain intensity after 5-7 days (primary); physicians' global assessment of improvement in pain and functional capacity; adverse events.
  
  
  RESULTS
  Flupirtine showed an overall pain-relieving efficacy comparable to tramadol. Mean LBP intensity after end of treatment dropped from 6.8 (95% CI: 6.5-7.0) to 2.8 (95% CI: 2.3-3.1) for flupirtine and from 6.9 (95% CI: 6.6-7.1) to 3.0 (95% CI: 2.6-3.4) for tramadol, corresponding to pain relief rates of 57% (95% CI: 51-63%) and 56% (95% CI: 50-62%) respectively (p = 0.796), indicating non-inferiority of flupirtine. All other efficacy endpoints supported equivalent efficacy. Adverse events (AEs) occurred significantly less in patients after flupirtine (33%) vs. tramadol (49%) (p = 0.02) and both the respective severity grading and the AE-related dropout rates were significantly lower after flupirtine than after tramadol (1% vs. 15%, p < 0.001).
  
  
  CONCLUSIONS
  Flupirtine 100 mg three times daily was associated with a reduction in pain and improvements in functional capacity equivalent to that observed with tramadol 50 mg three times daily, and was better tolerated, when administered to patients with subacute back pain for one week. The limitations of this study were the lack of a placebo control and the short (7-day) duration of the study.
authors.affiliation: Beijing University First Hospital, Beijing, China.
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Ni
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Gasparic
authors.forename: B
authors.initials: B
authors.lastname: Terhaag
authors.forename: M A
authors.initials: MA
authors.lastname: Uberall
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000631:Aminopyridines / Q000008:administration & dosage* / Q000009:adverse effects; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014147:Tramadol / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000631:Aminopyridines; D000701:Analgesics, Opioid; D014147:Tramadol; C034161:flupirtine