Using the weight-based pediatric dosing rule, if the adult acetaminophen dose is 15 mL and the child weighs 30 kg, what is the child's dose in mL?

Using the weight-based pediatric dosing rule, if the adult acetaminophen dose is 15 mL and the child weighs 30 kg, what is the child's dose in mL?

• A. 3 mL
• B. 5 mL
• C. 7.5 mL
• D. 9 mL

Answer: (A)

Weight-based pediatric dosing scales the dose to the child’s weight, using the adult dose as a reference and adjusting it proportionally. If the adult dose is 15 mL for an average adult weight of about 70 kg, the dose per kilogram is 15 mL / 70 kg ≈ 0.214 mL/kg. For a child weighing 30 kg, multiply: 30 kg × 0.214 mL/kg ≈ 6.4 mL per dose. Alternatively, acetaminophen dosing for children is often 10–15 mg/kg per dose; for a 30 kg child this is 300–450 mg per dose. With common liquid concentrations (for example, 160 mg/5 mL), that corresponds roughly to 9–14 mL per dose. These approaches show the dose should scale with weight rather than stay fixed; under standard weight-based scaling, the dose would be about 6.4 mL, not as low as 3 mL. If an answer choice states 3 mL, that likely reflects a different assumption about the reference weight or concentration and isn’t consistent with the typical weight-based method.

Weight-based pediatric dosing scales the dose to the child’s weight, using the adult dose as a reference and adjusting it proportionally. If the adult dose is 15 mL for an average adult weight of about 70 kg, the dose per kilogram is 15 mL / 70 kg ≈ 0.214 mL/kg. For a child weighing 30 kg, multiply: 30 kg × 0.214 mL/kg ≈ 6.4 mL per dose. Alternatively, acetaminophen dosing for children is often 10–15 mg/kg per dose; for a 30 kg child this is 300–450 mg per dose. With common liquid concentrations (for example, 160 mg/5 mL), that corresponds roughly to 9–14 mL per dose. These approaches show the dose should scale with weight rather than stay fixed; under standard weight-based scaling, the dose would be about 6.4 mL, not as low as 3 mL. If an answer choice states 3 mL, that likely reflects a different assumption about the reference weight or concentration and isn’t consistent with the typical weight-based method.