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.

Example:

  • 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.
1

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