Combination Antibiotics as a Treatment for Chronic Chlamydia-Induced Reactive Arthritis

Summary

A 9-month, prospective, double-blind, triple-placebo trial 1 assessed a 6-month course of combination antibiotics as a treatment for Chlamydia-induced reactive arthritis. Eligible patients had to be positive for Chlamydia trachomatis or Chlamydia pneumoniae by polymerase chain reaction (PCR). 42 patients were randomized to treatment groups (27 to combination antibiotics and 15 to placebo). Groups received doxycycline 100mg twice daily and rifampin 300mg daily, azithromycin 500mg daily × 5 days then twice weekly and rifampin 300mg daily, or matching placebos. The primary end point was the number of patients who improved by 20% or more in at least 4 of 6 variables without worsening in any 1 variable in both combination antibiotic groups combined and in the placebo group at month 6 compared with baseline.

The primary endpoint was achieved in 17/27 (63%) of the subjects on combination antibiotics vs. 3/15 (20%) on placebo (P-value = 0.01). Secondary efficacy end points showed similar results. Six of 27 patients (22%) randomized to combination antibiotics believed that their disease went into complete remission during the trial, whereas no patient in the placebo arm achieved remission (P-value = 0.07). Significantly more patients in the active treatment group became negative for C trachomatis or C pneumoniae by PCR at month 6. Adverse events were mild, with no significant differences between the groups.