Pharmacokinetics, safety, and efficacy of combination treatment with methotrexate and leflunomide in patients with active rheumatoid arthritis
Article first published online: 26 APR 2001
Copyright © 1999 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 42, Issue 7, pages 1322–1328, July 1999
How to Cite
Weinblatt, M. E., Kremer, J. M., Coblyn, J. S., Maier, A. L., Helfgott, S. M., Morrell, M., Byrne, V. M., Kaymakcian, M. V. and Strand, V. (1999), Pharmacokinetics, safety, and efficacy of combination treatment with methotrexate and leflunomide in patients with active rheumatoid arthritis. Arthritis & Rheumatism, 42: 1322–1328. doi: 10.1002/1529-0131(199907)42:7<1322::AID-ANR4>3.0.CO;2-P
- Issue published online: 26 APR 2001
- Article first published online: 26 APR 2001
- Manuscript Accepted: 16 FEB 1999
- Manuscript Received: 21 JUL 1998
- Hoechst Marion Roussel
To examine the safety and pharmacokinetics of and clinical response to leflunomide, a de novo pyrimidine synthesis inhibitor, when administered to patients with active rheumatoid arthritis (RA) who have been receiving long-term methotrexate therapy.
This was an open-label, 52-week study in which 30 patients with RA that remained active despite therapy with methotrexate at 17 ± 4 mg/week (mean ± SD) for ≥6 months were given leflunomide, 10–20 mg/day. Patients were assessed for adverse effects, pharmacokinetic measurements of leflunomide and methotrexate, and clinical response by American College of Rheumatology (ACR) 20% response criteria.
Twenty-three patients completed 1 year of treatment. No significant pharmacokinetic interactions between leflunomide and methotrexate were noted. This combination therapy was generally well tolerated clinically, with the exception of elevations of liver enzyme levels. Seven patients withdrew from the treatment regimen: 2 withdrawals were voluntary, 3 were due to persistent elevation of plasma transaminase levels, and 2 were due to lack of efficacy. Of the patients, 16 (53%) met ACR 20% response criteria. Two met ACR criteria for remission after 1 year.
The combination of methotrexate and leflunomide has therapeutic potential in RA.