Defined daily dose (DDD)

A unit of measurement to specify the assumed average maintenance dose per day for a medicines used for its main indication in the adult. A DDD will normally be only assigned for a substance after a product has been approved and marketed in at least one country. The basic principle is to assign only one DDD per route of administration within an ATC code. DDDs for plain substances are normally based on monotherapy. Doses for individual patients and patients groups will often differ from the DDD. A DDD does not necessarily reflect the recommended or Prescribed Daily Dose.
DDDs are not established for topical products, sera, vaccines, antineoplastic agents, allergen extracts, general and local anaesthetics and contrast media.

In German: Tagestherapiedosis (DDD)
Eine DDD ist der angenommene durchschnittliche Tagesverbrauch eines Arzneimittelwirkstoffes bei Anwendung in der Hauptindikation für eine erwachsene Person.

In Dutch: Defined Daily Dose (DDD) / standaarddagdosering
De theoretische gemiddelde onderhoudsdosis van een geneesmiddel, vastgesteld door de WHO, die door volwassenen per dag voor de hoofdindicatie wordt gebruikt. 

In Spanish: Dosis Diaria Definida (DDD)
La DDD es una unidad de medida que se define como la dosis media de mantenimiento por día para un medicamento utilizado en su indicación principal en un adulto. 

Last update: 15 June 2023

Source: WHO, adapted by PPRI