The disease modifying anti-rheumatic arthritis drug (DMARD), leflunomide does not have a higher risk of liver side effects than the traditional drug, but other newer DMARDs may, according to investigators at the Research Institute of the McGill University Health Center (MUHC). Their findings, presented today at the American College of Rheumatology Annual Scientific Meeting, show that this drug, leflunomide, has a similar effect on the liver as the traditional drug, methotrexate, and that newer biologic DMARDs may have greater risks.
"We decided to look specifically at the effect of leflunomide on the liver because of recent spontaneous reports with this drug," said MUHC Director of Clinical Epidemiology Dr. Samy Suissa and lead investigator of the study. "We found that patients taking leflunomide had the same risk of hepatic events than patients taking methotrexate."
Rheumatoid arthritis, a chronic inflammatory disease of joints and other internal organs, affects one out of 100 Canadians, and affects two million Americans. It leads to swelling, pain, stiffness, and possible loss of function and deformity of these joints. Treatments for rheumatoid arthritis are increasingly effective in slowing down this debilitating disease but their side effects can cause other health problems.
Dr. Suissa, also a professor at McGill University, and colleagues looked at data obtained from two large American health insurance companies that included 41,885 DMARD users. The DMARDs dispensed included leflunomide, the newer biologic DMARDs, methotrexate and other traditional DMARDs. Their study shows that the risk of serious hepatic events was significantly increased only with biological modifier DMARDs, not with leflunomide or other DMARDs.
"Evaluative studies such as these are extremely important in determining the best treatment options for patients while avoiding harm," said Suissa. "Our findings suggest the hepatic side effects observed with the biologic DMARDs must be investigated further."
The study was supported by Aventis, the makers of leflunomide.