In neonates, hepatic metabolism maturation influences drug clearance such that early dosing may require adjustments.

• A. No change in clearance with maturation
• B. Dosing intervals irrelevant
• C. Clearance may be increased
• D. Clearance may be reduced

Answer: (D)

Neonatal hepatic metabolism is not fully mature, so the liver’s ability to clear drugs is often reduced in early life. Phase I oxidation and Phase II conjugation pathways are underdeveloped at birth and gradually improve over weeks to months (more so in preterm infants). This underdevelopment prolongs drug half-life and increases exposure if dosing is not adjusted. Therefore, clearance may be reduced in neonates, which is why early dosing typically needs modification—smaller amounts or longer intervals—to avoid toxicity. The other ideas—no change, irrelevant dosing intervals, or increased clearance—don’t fit the typical maturation pattern, even though there are drug-specific exceptions.