What Factors Influence Drug Distribution in Children?
Several factors influence how drugs are distributed in children:
1. Body Water Composition: Infants have a higher percentage of total body water compared to adults. This affects the volume of distribution for hydrophilic drugs, often requiring different dosing strategies.
2. Body Fat: Neonates and young children have less body fat, which can alter the distribution of lipophilic drugs. This may lead to higher plasma concentrations of these medications.
3. Protein Binding: Plasma protein levels (such as albumin) are lower in neonates, affecting the binding of drugs. This can increase the free (active) fraction of a drug, necessitating careful monitoring and dosage adjustments.
4. Blood-Brain Barrier: The blood-brain barrier is more permeable in infants, potentially increasing the central nervous system effects of certain medications.
5. Organ Maturity: The liver and kidneys are immature in neonates, impacting drug metabolism and excretion. This can prolong the half-life of drugs and influence dosing intervals.
