Clark's rule
Weight-based formula for pediatric medication dosing.
Clark's rule is a medical formula used to calculate the appropriate dosage of medicine for children aged 2–17. It is based on the child's weight and the standard adult dose. The rule is named after Cecil Belfield Clarke, a Barbadian physician who practiced in the UK, the West Indies, and Ghana.
Quick Facts
- Named after
- Cecil Belfield Clarke
- Birth–death
- 1894–1970
- Age range
- 2–17 years
Facts from the source article.
Did You Know?
- Young's rule was named after Thomas Young, an English polymath, physician, and physicist.
- Kalman Fried lived from 1914 to 1999.
Overview
To apply Clark's rule, the child's weight in pounds is divided by 150 lb, and that fraction is multiplied by the adult dose. For example, a 30 lb child receiving an adult dose of 30 mg would get 6 mg. Although physicians often rely on manufacturer-recommended pediatric doses, familiarity with Clark's rule provides an extra safeguard against medication errors.
Fried's rule
Fried's rule is a similar formula adapted for infants, using the infant's age in months instead of weight. It was named after Kalman Fried, an Israeli geneticist and pediatrician who developed it while working at the Hadassah Medical Center in the 1960s. Fried was more widely known as a geneticist than as a pediatrician.
More in Rules of Thumb
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced