Better effect of methotrexate on C-reactive protein during daily compared to weekly treatment in rheumatoid arthritis.

Treatment with methotrexate (MTX) is well established in rheumatoid arthritis (RA), but dosing remains arbitrary as studies on the effect of different dosing schedules are lacking. In a randomised crossover design of 20 patients with RA, the effect of low (2.5mg) oral daily doses of MTX (15 mg weekly) was compared to intermittent weekly dosing (15 mg). C-reactive protein (CRP) values were lower and more stable on daily dosing compared to the significant (p < 0.05) changes in CRP observed during treatment with the same weekly dose. It may be postulated that nonresponders or patients with dose-dependent side effects may have clinical advantage from daily MTX dosing if hepatotoxicity and other side effects are not increased.