Dosing time-dependency of the arthritis-inhibiting effect of tacrolimus in mice.

Stiffness and cytokine in blood levels show 24-h rhythms in rheumatoid arthritis (RA) patients. We previously revealed that higher therapeutic effects were obtained in RA patients and RA model animals when the dosing time of methotrexate was chosen according to the 24-h rhythms to cytokine. In this study, we examined whether a dosing time-dependency of the therapeutic effect of tacrolimus (TAC) could be detected in collagen-induced arthritis (CIA) and MRL/lpr mice.