title: Plasma concentrations of fentanyl in infants, children and adults.
abstract: To evaluate whether there are age-related differences in the plasma concentration-vs-time course of fentanyl, the authors administered fentanyl to seven infants (3-10 months), seven children (1-9 years) and seven adults (18-41 years). Anaesthesia was induced with thiopentone, nitrous oxide, and pancuronium; following tracheal intubation, fentanyl (approximately 30 micrograms X kg-1 for infants and children, 20 micrograms X kg-1 for adults) was administered as a 2-min IV infusion. Anaesthesia was maintained with nitrous oxide, pancuronium, and morphine sulphate as clinically indicated. Plasma samples were obtained for 4 h and fentanyl concentrations determined by radioimmunoassay. Plasma concentrations per microgram X kg-1 fentanyl administered were lowest in infants 4-10 and 60-240 min after the start of the 2-min infusion; values for children were lower than those for adults 4, 180 and 210 min after the start of the 2-min infusion. These findings are consistent with the authors' clinical observation that infants tolerate larger doses of fentanyl than do adults.
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005283:Fentanyl / Q000097:blood*; D006801:Humans; D007223:Infant
chemical_list: D005283:Fentanyl