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The Anatomical Therapeutic Chemical (ATC) Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological, and chemical properties. It is controlled by the World Health Organization Collaborating Centre for Drug Statistics Methodology (WHOCC).

Inasmuch as the ATC codes are semantic identifiers, the ATC vocabulary was taken as a basis for the OMOP Drug hierarchy.

As of 7 May 2020, there are 6,331 codes in ATC.


All ATC concepts belong to the “Drug” domain.

Concept Classes

concept_class_id description
ATC 1stAnatomical main group
ATC 2ndTherapeutic subgroup
ATC 3rdPharmacological subgroup
ATC 4thTherapeutic/pharmacological/chemical subgroup
ATC 5thChemical substance subgroup (ingredients or combinations)
documentation/vocabulary/atc.txt · Last modified: 2020/07/16 23:02 by ptalapova