For which group of patients should dosages typically be calculated by weight?

Calculating dosages by weight is particularly important for children due to their varying body sizes and developmental stages. Children's metabolic rates and how they respond to medications differ significantly from adults, so a standard adult dosage may not be appropriate. Adjusting medication dosages based on a child's weight helps ensure efficacy while minimizing the risk of overdose or adverse reactions, as children are more sensitive to medications.

In contrast, while dosages could also vary in very large adults or in the elderly, these factors are generally better managed with standard dosing guidelines that do not require weight-based adjustments. Small adults may also benefit from weight considerations, but children are the primary focus for such individualized dosing calculations due to their rapid growth and unique physiological characteristics.