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.
|ATC 1st||Anatomical main group|
|ATC 2nd||Therapeutic subgroup|
|ATC 3rd||Pharmacological subgroup|
|ATC 4th||Therapeutic/pharmacological/chemical subgroup|
|ATC 5th||Chemical substance subgroup (ingredients or combinations)|