Single-dose pharmacokinetics of roflumilast in children and adolescents

Roflumilast is an orally administered phosphodiesterase 4 inhibitor that has potential for use in pediatric patients with asthma. The pharmacokinetics of roflumilast and roflumilast N-oxide were examined in adolescents and children with stable mild to moderate asthma in an open-label crossover study with age-stratification and 2 treatment periods (100-microg dose in period 1, 250-microg dose in period 2) separated by a washout period. Plasma concentrations were measured by high-performance liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were determined using standard noncompartmental methods and compared between study groups and within the entire cohort. Roflumilast was well tolerated. Linear relationships were evident for dose and area under the plasma drug concentration-time curve extrapolated to infinity for both roflumilast (r(2) = 0.36, P < .01) and roflumilast N-oxide (r(2) = 0.39, P < .01). With the exception of dose-normalized maximum plasma concentration (mean 1.1 and 0.8 microg/L per 1 microg/kg dose for adolescents and children, respectively), pharmacokinetic parameters for roflumilast and roflumilast N-oxide were not different between age groups and were similar to adults.