Massachusetts Pharmacy Technician License Exam Prep 2025 – Complete Practice Test

To determine the child's dose using Clark's rule, the formula involves the child's weight in pounds compared to a standard adult weight, which is typically set at 150 pounds. Clark's rule is expressed as follows:

- Child's dose = (Weight of child in pounds / 150) x Adult dose

In this scenario, the child weighs 75 pounds and the adult dose is 400 mg. Plugging the numbers into the formula gives:

- Child's dose = (75 / 150) x 400 mg

- Child's dose = 0.5 x 400 mg

- Child's dose = 200 mg

This calculation provides the correct child's dosage based on Clark's rule, demonstrating how the child's weight proportional to the standard adult weight scales down the adult dose appropriately for a safer and more effective pediatric dosing. The chosen answer reflects this calculation accurately.