title: Randomised, blinded, placebo controlled trial of doxycycline for chronic seronegative arthritis.
abstract: OBJECTIVE
  To determine whether long term doxycycline improves symptoms in patients with chronic seronegative or reactive arthritis.
  
  
  METHODS
  A randomised, triple blind, controlled clinical trial of three months' treatment with doxycycline or placebo of patients with chronic reactive or seronegative arthritis was conducted. The primary study end points were three month pain and functional status measured by a self administered Arthritis Impact Measurement Scales version 2 (AIMS2) quality of life questionnaire. Secondary end points were pain and functional status at 6-12 months, three month rheumatologist assessed joint count, pain, and arthritis activity, and treatment efficacy in those with previous exposure to chlamydia.
  
  
  RESULTS
  Of 60 patients randomly allocated to receive doxycycline or placebo, results from 37 were evaluable at three months. Groups were well balanced for major prognostic variables. Doxycycline had no detectable effect at three months on pain change scores (mean difference 1.5, 95% CI -1.2 to 4.2, p=0.25) or composite functional change scores (mean difference 0.8, 95% CI -5.6 to 7.1, p=0.81). Furthermore, there were no differences in secondary study end points, and no apparent treatment effect in patients with previous chlamydia infection.
  
  
  CONCLUSIONS
  Three months' treatment with doxycycline did not improve pain or functional status in patients with chronic reactive or seronegative arthritis.
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada. smiejam@mcmaster.ca
authors.forename: M
authors.initials: M
authors.lastname: Smieja
authors.forename: D W
authors.initials: DW
authors.lastname: MacPherson
authors.forename: W
authors.initials: W
authors.lastname: Kean
authors.forename: M L
authors.initials: ML
authors.lastname: Schmuck
authors.forename: C H
authors.initials: CH
authors.lastname: Goldsmith
authors.forename: W
authors.initials: W
authors.lastname: Buchanan
authors.forename: L E
authors.initials: LE
authors.lastname: Hart
authors.forename: J B
authors.initials: JB
authors.lastname: Mahony
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001168:Arthritis / Q000188:drug therapy* / Q000503:physiopathology; D016918:Arthritis, Reactive / Q000188:drug therapy / Q000503:physiopathology; D002908:Chronic Disease; D004311:Double-Blind Method; D004318:Doxycycline / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010349:Patient Compliance; D011788:Quality of Life; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D004318:Doxycycline