Singulair - Clinical Pharmacology

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Pharmacokinetic studies evaluated the systemic exposure of the 4-mg oral granule formulation in pediatric patients 6 to 23 months of age, the 4-mg chewable tablets in pediatric patients 2 to 5 years of age, the 5-mg chewable tablets in pediatric patients 6 to 14 years of age, and the 10-mg film-coated tablets in young adults and adolescents 15 years of age. The plasma concentration profile of montelukast following administration of the 10-mg film-coated tablet is similar in adolescents 15 years of age and young adults. The 10-mg film-coated tablet is recommended for use in patients 15 years of age. The mean systemic exposure of the 4-mg chewable tablet in pediatric patients 2 to 5 years of age and the 5-mg chewable tablets in pediatric patients 6 to 14 years of age is similar to the mean systemic exposure of the 10-mg film-coated tablet in adults. The 5-mg chewable tablet should be used in pediatric patients 6 to 14 years of age and the 4-mg chewable tablet should be used in pediatric patients 2 to 5 years of age.

In children 6 to 11 months of age, the systemic exposure to montelukast and the variability of plasma montelukast concentrations were higher than those observed in adults. Based on population analyses, the mean AUC (4296 ng° hr/ mL [range 1200 to 7153]) was 60% higher and the mean Cmax (667 ng/ mL [range 201 to 1058]) was 89% higher than those observed in adults (mean AUC 2689 ng° hr/ mL [range 1521 to 4595]) and mean Cmax (353 ng/ mL [range 180 to 548]). The systemic exposure in children 12 to 23 months of age was less variable, but was still higher than that observed in adults. The mean AUC (3574 ng° hr/ mL [range 2229 to 5408]) was 33% higher and the mean Cmax (562 ng/ mL [range 296 to 814]) was 60% higher than those observed in adults.

Safety and tolerability of montelukast in a single-dose pharmacokinetic study in 26 children 6 to 23 months of age were similar to that of patients two years and above (see ADVERSE REACTIONS). The 4-mg oral granule formulation should be used for pediatric patients 12 to 23 months of age. Since the 4-mg oral granule formulation is bioequivalent to the 4-mg chewable tablet, it can also be used as an alternative formulation to the 4-mg chewable tablet in pediatric patients 2 to 5 years of age.