TABLE 1

Serum and brain methylphenidate concentrations

Data are presented as the mean ± S.E.M. (n = 9–10/group, randomly selected from the total sample). Methylphenidate concentrations were determined 20 min after administration. For serum concentrations, there were significant main effects of dose (P < 0.0001) and age (P < 0.0001) with all age groups different from each other (P < 0.05) but no significant interaction. One outlier was removed from the P70 5 mg/kg group. For brain concentrations, there were significant main effects of dose (P < 0.0001) and age (P < 0.0001) with concentrations higher at P70 and P42 than at P35 (both P < 0.001) but no significant interaction. One outlier was removed from the P35 2.5 mg/kg group.