Therapeutic drug monitoring of teriflunomide: do plasma concentrations predict response to leflunomide in patients with rheumatoid arthritis?

Objectives: Leflunomide is a commonly used treatment for rheumatoid arthritis. It acts by inhibiting dihydroorotate dehydrogenase through its active metabolite teriflunomide. The objective of the study was to investigate the relation between plasma-concentration of teriflunomide and disease-activity in rheumatoid arthritis.