Urinary excretion of placentally transferred thiopentone by the human neonate.
The urinary excretion of thiopentone and its metabolite, pentobarbitone, was studied in 7 neonates whose mothers-had received thiopentone. During the urine collection period (range 39.3-63.8 h), a mean of 26.4 micrograms thiopentone was recovered, representing only a mean of 0.0066% of the maternal dose. This suggests that the elimination of thiopentone by the neonate occurs mainly by metabolism. The metabolite pentobarbitone could not be detected. Mean elimination half-life of thiopentone, calculated from sigma-minus plots, was 8.04 h which is similar to the value reported previously in adults. This contrasts with other barbiturates which show much longer half-lives in neonates than in adults.
D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D008297:Male; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D013874:Thiopental / Q000097:blood / Q000652:urine*; D013997:Time Factors
D013874:Thiopental