Pharmacokinetic evaluation of teriflunomide for the treatment of multiple sclerosis.

INTRODUCTION: Teriflunomide is an immunomodulatory drug that received FDA approval for the treatment of relapsing forms of multiple sclerosis (MS) in September 2012. Its primary mode of action is inhibition of dihydroorotate dehydrogenase which inhibits the proliferation of activated T cells, but it also has a number of other actions that may be important contributors to its efficacy in MS. AREAS COVERED: This review covers a basic pathophysiology of MS and the current treatment options, including a discussion of the needs for additional treatments. The main focus of the review is the pharmacokinetics and pharmacodynamics of teriflunomide, including a brief comparison with the disease-modifying antirheumatic drug leflunomide. The authors discuss the clinical efficacy and toxicity profile of teriflunomide and make some comparisons with treatments that are currently, or soon to be available. EXPERT OPINION: While teriflunomide is no more effective than a number of other agents that are used in the treatment of MS, it has a favorable side-effect profile and the convenience of once a day oral administration. As such, it is likely to be a popular agent in the treatment of MS over the next 5 years.