The elimination half life in the 2 to 11 and 12 to 18 year age groups (1.4 ± 0.3 and 1.6± 0.3 h-1, respectively) is shorter than that observed in the two adult populations (1.9 ± 0.5 and 2.5± 0.5 h-1 in the 19 to 64 and ≥ 65 year of age groups, respectively).