Leflunomide

Leflunomide, a conventional synthetic DMARD, was used as a second-line treatment for rheumatoid arthritis, particularly when methotrexate was contraindicated or ineffective. It worked by inhibiting lymphocyte proliferation and reducing proinflammatory gene expression. Clinical trials showed leflunomide had good efficacy compared to placebo and similar efficacy to sulfasalazine and methotrexate, with some studies indicating it delayed radiographic progression more than methotrexate. However, it had significant side effects, including gastrointestinal disturbances, liver function test elevation, alopecia, and peripheral neuropathy, necessitating regular monitoring. Despite its benefits, the advent of safer biological drugs reduced the likelihood of further studies on leflunomide for other conditions like type 1 diabetes.