“…Tacrolimus (Prograf) and cyclosporine (Neoral), both of which are now frequently used in Japan after being approved by medical insurance, are both calcineurin inhibitors, and their mechanism of action is to suppress T-cell activity. In Japan, tacrolimus was covered by insurance several years before cyclosporin, and has been used safely in many pediatric patients, 3,93,94 whereas cyclosporin is still relatively rarely used, 3,92 but has been reported to be effective against MuSK-MG. 95 Tacrolimus is used at a fixed dose of 3 mg/d in adults, 96,97 but in children it is started at a dose of 0.05 mg/kg/d once daily, taking body weight into consideration, and then at a dose of 0.1-0.2 mg/kg/d once daily. 94,98 It is usually administered after dinner, and the trough blood level is measured in the morning of the next day and adjusted, aiming for a concentration of 3-5 ng/mL, and without exceeding 10 ng/mL.…”