This is a pharmacoeconomic term for the average maintenance dose for the clinical indication of a drug in adult patient.The Defined daily doses (DDDs) are a WHO (The World Health Organization) statistical measure of drug consumption.

A common concern when comparing drugs is that medications can be of different strengths and different potency. However problems can arise when companies attempt to compare 1mg of one medication, with 1mg of another, especially when different countries use different doses. DDD stated aim to solve this by relating all drug use to a standardized unit which is analogous to one day’s worth.