Age-related differences in the protein binding of quinidine.
The in vitro serum protein binding of quinidine was determined in 26 pediatric patients. Group I consisted of 6 cord blood samples obtained at the time of delivery, group II of 8 infants aged 8-18 months, and group III of 12 children over the age of 2 years. The percentage of free quinidine in group I was 39.2 +/- 10.8, group II 24.4 +/- 10.6 and group III 16.6 +/- 6.5, demonstrating a larger proportion of unbound quinidine in the newborn group and an increase in protein binding with age (p less than 0.0001). Therefore, the protein binding of quinidine is diminished in the neonate and young infant and may result in enhanced quinidine activity.
D000375:Aging; D001798:Blood Proteins / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D011247:Pregnancy; D011485:Protein Binding; D011802:Quinidine / Q000378:metabolism*
D001798:Blood Proteins; D011802:Quinidine