Final answer:
The decreased protein-binding capacity in preterm infants requires careful adjustment of drug dosages to avoid toxicity. As the immature hepatic and renal function affects drug metabolism and clearance, lower doses of protein-binding drugs may be necessary. Additionally, the more permeable blood-brain barrier in preterm infants also influences drug dose adjustments.
Step-by-step explanation:
Due to the decreased protein-binding capacity in preterm infants, adjustments in the dosage of protein-binding drugs would be required. In preterm infants, the binding capacity of albumin is reduced, which affects both the drug's distribution and its clearance from the body. Since only the unbound fraction of the drug can exert a pharmacological effect, and preterm infants have a higher ratio of free drug due to decreased protein binding, lower doses of such drugs might be necessary to avoid toxicity .It is also important to note that the immature hepatic and renal function in preterm infants reduces the metabolic clearance of drugs. The liver enzyme UDP glucuronyl transferase, which is necessary for bilirubin conjugation, is not fully developed in preterm infants. Drugs that undergo hepatic metabolism might therefore have a prolonged half-life in the body, necessitating careful dosage adjustments. Furthermore, the blood-brain barrier (BBB) in preterm infants is more permeable, increasing the risk for drugs, particularly those that are highly protein-bound, to penetrate into the central nervous system and potentially cause adverse effects. Medications with a high affinity for protein binding may require dose reductions or careful monitoring when administered to preterm infants to mitigate the risks of drug toxicity and adverse effects.