Anti-malarial drug Plaquenil (hydroxychloroquine) may help reduce the risk of the development of type 2 diabetes in patients with rheumatoid arthritis, according to a report in the July 11 issue of the Journal of the American Medical Associaton (JAMA).

Antimalarials such as hydroxychloroquine, a long-standing safe and inexpensive treatment for an autoimmune disease such as rheumatoid arthritis, theoretically may improve glucose tolerance and prevent diabetes mellitus, according to University of Pittsburgh researchers.

Dr. Mary Chester M. Wasko and colleagues examined the association between hydroxychloroquine therapy and risk of diabetes in a study that included 4,905 adults with rheumatoid arthritis who had never been diagnosed with or treated for diabetes.

Over two decades, the researchers found that patients who had taken hydroxychloroquine had a 38 percent lower risk of developing diabetes than those who had not taken hydroxychloroquine.

Patients who took hydroxychloroquine for more than four years had a 77 percent lower risk of diabetes compared with those who had never taken hydroxychloroquine.

“Risk reduction increased with duration of hydroxychloroquine exposure, supporting a biological action of this drug on glucose metabolism," the researchers reported.

"Further prospective studies are needed to determine whether this treatment option should be considered a standard component of rheumatoid arthritis combination therapy in the future, and to evaluate the potential role of hydroxychloroquine as a preventive agent for diabetes among high-risk individuals in the general population,” the researchers concluded.