The primary care NP is considering use of a relatively new drug for a 15-month-old; the drug is metabolized by the liver; what dosing approach is likely?

The primary care NP is considering use of a relatively new drug for a 15-month-old; the drug is metabolized by the liver; what dosing approach is likely?

• A. More often or at a higher dose.
• B. Less often or at a lower dose.
• C. Via a parenteral route.
• D. Via the oral route.

Answer: (B)

When a drug is cleared mainly by the liver, the child’s liver enzyme systems determine how quickly the drug is broken down. At 15 months, these hepatic pathways are not yet at adult capacity, so drug clearance is slower than in adults. A given adult dose would therefore produce higher exposure and a greater risk of toxicity in a toddler. To avoid that, dosing is typically reduced or given less frequently (lower mg/kg dose or longer dosing interval) until the child’s metabolism matures further. The route of administration is less relevant to this adjustment; the key is accommodating immature hepatic metabolism.

When a drug is cleared mainly by the liver, the child’s liver enzyme systems determine how quickly the drug is broken down. At 15 months, these hepatic pathways are not yet at adult capacity, so drug clearance is slower than in adults. A given adult dose would therefore produce higher exposure and a greater risk of toxicity in a toddler. To avoid that, dosing is typically reduced or given less frequently (lower mg/kg dose or longer dosing interval) until the child’s metabolism matures further. The route of administration is less relevant to this adjustment; the key is accommodating immature hepatic metabolism.