Clark's rule is a medical term referring to a mathematical formula used to calculate the proper dosage of medicine for children aged 2–17 based on the weight of the patient and the appropriate adult dose.
[1] The formula was named after Cecil Belfield Clarke (1894–1970), a Barbadian physician who practiced throughout the UK, the West Indies and Ghana.
Though it is more common for physicians to use medications that have suggested manufacturer's doses for children, familiarity of Clark's rule is used as an additional layer of protection against potentially deadly medication errors in clinical practice.
[6] The formula is nearly identical, except with the child's weight replaced by the infant's age in months.
Fried's rule was named after Kalman Fried (1914–1999), an Israeli geneticist and pediatrician who developed his own formula while treating and observing children at the Hebrew University of Jerusalem-affiliated Hadassah Medical Center in the 1960s.