title: Randomized placebo controlled trial of lofexidine hydrochloride for chronic pelvic pain in women.
abstract: BACKGROUND
  We hypothesised that the orally-active alpha(2)-adrenoceptor agonist lofexidine hydrochloride would ameliorate chronic pelvic pain in women.
  
  
  METHODS
  A randomized placebo-controlled parallel group trial was undertaken in the University Hospital Gynaecology Clinic. Women with pelvic pain of at least 6 months duration were eligible, and were randomized using a sealed envelope system to receive up to 600 mg lofexidine hydrochloride twice daily over 8 weeks or placebo. Outcome measures were summary and daily diary visual analog scales for pain (VAS) and a 5 point self rating scale.
  
  
  RESULTS
  9/19 women randomized to lofexidine completed the study compared to 14/20 of those randomized to placebo. Intention-to-treat analysis showed that 4/19 in the lofexidine group achieved 50% or greater reduction in VAS compared with 8/20 in the placebo group (OR 2.5, 95% CI 0.6--10.3). Summary and diary VAS were closely correlated.
  
  
  CONCLUSIONS
  Within the limits of a small study with power to detect only a substantial effect, we conclude that lofexidine hydrochloride is not effective for the treatment of chronic pelvic pain.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Southampton, Southampton, UK. rws1@soton.ac.uk
authors.forename: R W
authors.initials: RW
authors.lastname: Stones
authors.forename: L
authors.initials: L
authors.lastname: Bradbury
authors.forename: D
authors.initials: D
authors.lastname: Anderson
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000627:therapeutic use; D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000627:therapeutic use; D015992:Body Mass Index; D002908:Chronic Disease; D003000:Clonidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use*; D003061:Codeine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D017699:Pelvic Pain / Q000188:drug therapy*; D010919:Placebos; D016896:Treatment Outcome
chemical_list: D000316:Adrenergic alpha-Agonists; D000894:Anti-Inflammatory Agents, Non-Steroidal; D010919:Placebos; D000082:Acetaminophen; D003000:Clonidine; C014481:dihydrocodeine; C025655:lofexidine; D003061:Codeine