Study: Side Effects Lead Some Rheumatoid Arthritis Patients to Stop Leflunomide

The rheumatoid arthritis drug leflunomide at high doses may cause adverse side effects that lead some patients to stop taking the drug, according to a study reported in the Dec. 15 issue of the journal Arthritis Care & Research.

The U.S. Food and Drug Administration (FDA) approved the use of leflunomide for rheumatoid arthritis in October 1998 and recommends starting treatment with high doses to rapidly trigger the drug's benefits.

Researchers at the Veterans Affairs Medical Center and Washington University School of Medicine in St. Louis analyzed a national database of patients at veterans' hospitals to investigate the effects of the rheumatoid arthritis drug leflunomide in the first years after its approval.

"Our data suggest that by starting on a lower dose initially, patients tolerate the drug better," said Dr. Seth Eisen, a Veterans Affairs staff physician and professor of medicine and psychiatry at Washington University School of Medicine. "The disadvantage is that it may take a little bit longer for patients to improve clinically; the advantage is that patients may be more likely to continue treatment."

According to the researchers, the study suggests that physicians should consider slightly modifying the standard leflunomide treatment regimen. The new findings also help put to rest lingering concerns about whether leflunomide's toxicity was adequately assessed in clinical trials that ended in 1998.

"As far as we could tell there were no surprises in terms of toxicity," Eisen said. "Sometimes it takes a lot more patients than the 3,300 we studied to pick up rare adverse outcomes, but I think our findings are reassuring to the larger community of patients and clinicians."

Eisen suggests that researchers should consider conducting studies on drugs some time after they have been approved because it may reveal problems that weren't anticipated at the time of approval.

Other sources: Washington University School of Medicine