Lack of effect of doxycycline on disease activity and joint damage in patients with rheumatoid arthritis. A double blind, placebo controlled trial

Objective. To investigate the effects of doxycycline on disease activity an d joint destruction in patients with rheumatoid arthritis (RA). Methods. A 36 week double blind, placebo controlled crossover trial was con ducted. Patients (n=66) received 50 mg doxycycline or placebo twice a day d uring 12, 24, or 36 weeks. Patient assessments were performed before the tr eatment was administered, at 6, 12, 24 and 36 weeks of treatment, and final ly at 4 weeks after cessation of treatment. Patient assessments, swollen an d tender joint counts, duration of morning stiffness, erythrocyte sedimenta tion rate, and Modified Disease Activity Score were used as measures of dis ease activity. Effects on joint destruction were assessed by urinary excret ion of the pyridinolines hydroxylysylpyridinoline and lysylpyridinoline and by scoring radiographic damage of hands and feet before and after treatmen t. Results. The changes of clinical or laboratory disease activity measures, p yridinoline excretion, or progression of radiographic joint damage during d oxycycline or placebo treatment did not differ significantly. Conclusion. The results indicate that 50 mg doxycycline twice a day provide d no therapeutic benefit for patients with RA.