Pharmacokinetics and renal function in patients with rheumatoid arthritis receiving a standard dose of oral weekly methotrexate: association with significant decreases in creatinine clearance and renal clearance of the drug after 6 months of therapy.

Abstract

No differences in AUC, Tmax, or Cmax were observed over a 2 year period in patients with rheumatoid arthritis on a standard 7.5 mg dose of MTX. Renal clearance and creatinine clearance both decreased significantly after 6 months of treatment. This effect may be clinically relevant in certain individuals as MTX is renally excreted.