Clinical pharmacokinetics and relative bioavailability of oral procaterol

The pharmacokinetics and relative oral bioavailability of procaterol, an orally active beta 2-adrenergic agonist bronchodilator were evaluated in healthy volunteers. Procaterol was rapidly absorbed after oral administration. Mean plasma procaterol concentration-time profiles and pharmacokinetic parameters for both formulations were essentially superimposable. Following tablet administration, the mean Cmax was 358 pg/mL and the corresponding mean tmax was 1.6 hr. Mean renal clearance was 163 mL/min and accounted for approximately one-sixth of the mean apparent oral plasma clearance (988 mL/min). The mean apparent elimination half-life of procaterol was 4.2 hr. Hepatic metabolism appears to be the primary mechanism for elimination of procaterol from the body, and first-pass metabolism may limit systemic bioavailability.