13.1: Drug Dosing: Infants and Children

Pediatric patient dosages diverge from adults due to disparities in body surface area, total body water, and extracellular fluid per kilogram of body weight. The dosing regimen considers the variations in pharmacokinetics and pharmacology across distinct age groups, encompassing preterm newborns, infants, young children, older children, and adolescents. Calculation of pediatric patient doses is predicated on determining body surface area, which exhibits a superior correlation with the child's dosage requirement, cardiac output, renal blood flow, and glomerular filtration.

Notably, pediatric patients necessitate larger doses than adults owing to their augmented body surface area and volume of distribution (V_D). This is further compounded by the fact that neonates possess 15–30% more total body water than adults, resulting in an increased V_D for hydrophilic drugs and a diminished V_D for lipophilic drugs, thereby mandating dosage adjustments. In addition to modifying the dosage amount, dosing schedules and frequency may also require adjustments due to differences in drug metabolism and clearance rates among pediatric patients. Furthermore, pediatric dosage forms predominantly encompass liquid products equipped with calibrated droppers and cherry flavor, ensuring precise dosing and bolstering patient compliance.

Pediatric patients require different dosages than adults due to variations in body surface area, total body water, and extracellular fluid per kg body weight.

Dosing also considers pharmacokinetics and pharmacology differences across various age groups, including preterm newborns, infants, young children, older children, and adolescents.

The pediatric dose can be calculated using various formulae based on body surface area, age, or weight. This helps to better correlate with a child’s dosage requirements, cardiac output, renal blood flow, glomerular filtration, and organ maturity.

Pediatric patients often require larger doses than adults due to their larger body surface area and V_D,

Neonates typically have more total body water than adults, resulting in a larger V_D for hydrophilic drugs and a smaller V_D for lipophilic drugs.

They also have immature organs, necessitating dosage adjustments.

Additionally, pediatric dosage forms often involve liquid formulations with calibrated droppers and added flavors, allowing for accurate dosing and patient compliance.