Morphine pharmacokinetics in early infancy.
The pharmacokinetics of morphine in ten infants less than or equal to 10 weeks of age who were receiving morphine infusions were determined. Infants 1-4 days of age (newborns) showed longer elimination half-lives than the older infants (6.8 vs. 3.9 h). Clearance in the newborns is less than one-half that found in older infants (6.3 vs. 23.8 ml X min-1 X kg-1). The combination of lower clearance and longer elimination half-life in newborns (0-7 days) may well explain a prolonged duration of action for morphine in very young infants, but other etiologies are needed to explain the respiratory sensitivity believed to persist in older infants.
D005260:Female; D006207:Half-Life; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007262:Infusions, Intravenous; D007700:Kinetics; D008171:Lung Diseases / Q000188:drug therapy; D008297:Male; D009020:Morphine / Q000378:metabolism* / Q000627:therapeutic use; D012121:Respiration, Artificial
D009020:Morphine