Albumin and Other Plasma Proteins in Pediatric Patients: What, When, and How Much They Influence Antimicrobial Pharmacology.

Plasma proteins play a critical role in antimicrobial drug exposure, particularly in special populations where protein concentrations and binding capacity may be altered. This review summarizes current knowledge on age-related changes in plasma protein concentrations and protein-binding variability, with a specific focus on pediatric populations. This variability can lead to substantial alterations in the unbound fraction of many antimicrobials, especially those that are highly protein-bound. Understanding these pharmacokinetic changes is fundamental for safe and effective antimicrobial dosing in particular patients such as pediatric patients, who may require specific dose adjustments based on the various stages of their physiological development, from birth to adolescence. During this growth period, each developmental stage may represent a clinical setting with distinctive characteristics that clinicians must consider when choosing the drug and its dosage, because pharmacokinetic parameters may change within a shorter and more variable time frame than observed in adult patients. In this context therapeutic drug monitoring (TDM) represents a key strategy for optimizing drug dosing and achieving target therapeutic drug concentrations.