11-24-2003 Tetracyclines, especially minocycline, reduce disease activity in patients with rheumatoid arthritis (RA), according to results of a metaanalysis published in the Journal of Rheumatology for October.
Investigators in Ontario, Canada, reviewed 10 randomized controlled trials comparing the effectiveness of tetracyclines to either placebo or conventional disease-modifying antirheumatic drugs (DMARD) for the prevention or reduction of disease activity in a total of 535 RA patients.
Only 3 trials were considered "high quality," and "elements of bias could not be excluded in the remainder," the investigators note.
With these caveats in mind, the researchers report that tetracyclines, when administered for at least 3 months, "were associated with a reduction in disease activity with no absolute increased risk of side effects compared to controls, but no statistically significant reduction in joint damage."
The treatment effect was more pronounced in patients with disease duration of less than one year who were seropositive for rheumatoid factor and in those treated with minocycline.
When considering both minocycline and doxycycline therapy, "the magnitude of the reduction in disease activity was small for joint counts, but large for acute phase reactants," Dr. Millicent Stone of Toronto Western Hospital and colleagues report.
These two agents have "important" anti-inflammatory activity in addition to their antibiotic properties, "which is a likely explanation of the dramatic improvement in acute phase reactants in the absence of substantial clinical disease activity improvement," they write.
Additional studies comparing the safety, efficacy and cost-effectiveness of tetracyclines to that of newer DMARDs are warranted, the team concludes.
Tetracyclines have a "potentially important role [in the RA], which may have been overlooked with the advent of newer agents," they write.
Commenting on the study, Drs. Hilary A. Capell and Rajan Madhok from Glasgow Royal Infirmary in Scotland say in an editorial in the journal, "Minocycline appears to achieve benefit similar to drugs that we accept as useful DMARD."
They add, "While data relating to adverse events may be sparse, this metaanalysis provides a useful summary of the value of tetracyclines in RA for the practicing physician considering their use."
J Rheumatol 2003;30:2085-2087,2112-2122.
For more information about arthritis, please visit www.ArthritisSupport.com.