Pseudoephedrine is readily and almost completely absorbed from the GI tract and there is no evidence of first-pass metabolism. Following oral administration of a 60- or 120-mg dose of pseudoephedrine hydrochloride as an oral solution, peak plasma concentrations of about 180-300 or 397-422 ng/mL, respectively, were achieved in approximately 1.39-2 or 1.84-1.97 hours, respectively. Absorption from extended-release preparations is slower and peak plasma concentrations of the drug are achieved in about 3.8-6.1 hours. Following oral administration of single 30- or 60-mg doses of pseudoephedrine hydrochloride as a solution in pediatric patients (6-12 years of age), mean peak serum concentrations of 244 or 492 ng/mL, respectively, were achieved after 2.1 or 2.4 hours, respectively. Food delays absorption of the drug when administered as a solution, but appears not to have an effect on absorption when the drug is administered as extended-release preparations