Plasma protein binding

Plasma protein binding

Many drugs have a lower plasma protein binding and thus larger free serum concentration in young children in comparison with adults. This is usually due to a lower concentration of binding proteins, like albumin in the circulation. A larger free concentration of a drug in the circulation implies that also a larger amount is available for degradation and clearance. The plasma albumin concentration reaches adult levels around 1 year of age.





  • antibacterial drugs like sulphonamides and ampicillin have high free plasma concentrations in neonates.
  • sulphonamides can compete with bilirubin for plasma albumin. This competition can cause hyperbilirubinemia and risk for icterus.



Which of the following is NOT the result of the lower concentrations of binding proteins in pediatric patients?