The '''Anatomical Therapeutic Chemical Classification System''' is used for the [[taxonomic classification|classification]] of [[Medication|drug]]s. It is controlled by the [[World Health Organization|WHO]] Collaborating Centre for Drug Statistics Methodology, and was first published in [[1976]].

The classification system divides drugs into different groups according to the organ or system on which they act and/or their [[medicine|therapeutic]] and [[chemical classification|chemical characteristics]].

== Classification ==

In this system, drugs are classified into groups at 5 different levels:

=== First level ===

The first level of the code is based on a letter for the anatomical group and consists of one letter; there are 14 main groups:

{| class="wikitable"
|-
| A
| [[ATC code A|Alimentary tract and metabolism]]
|-
| B
| [[ATC code B|Blood and blood forming organs]]
|-
| C
| [[ATC code C|Cardiovascular system]]
|-
| D || [[ATC code D|Dermatologicals]]
|-
| G
| [[ATC code G|Genito-urinary system and sex hormones]]
|-
| H
| [[ATC code H|Systemic hormonal preparations, excluding sex hormones and insulins]]
|-
| J
| [[ATC code J|Anti-infectives for systemic use]]
|-
| L
| [[ATC code L|Antineoplastic and immunomodulating agents]]
|-
| M
| [[ATC code M|Musculo-skeletal system]]
|-
| N || [[ATC code N|Nervous system]]
|-
| P
| [[ATC code P|Antiparasitic products, insecticides and repellents]]
|-
| R || [[ATC code R|Respiratory system]]
|-
| S || [[ATC code S|Sensory organs]]
|-
| V || [[ATC code V|Various]]
|}

=== Second level ===

The second level of the code is based on the therapeutic main group and consists of two digits.

=== Third level ===

The third level of the code is based on the therapeutic/pharmacological subgroup and consists of one letter.

=== Fourth level ===

The fourth level of the code is based on the chemical/therapeutic/pharmacological subgroup and consists of one letter.

=== Fifth level ===

The fifth level of the code is based on the chemical substance subgroup and consists of two digits.

==See also==
* [[Wikipedia:WikiProject Pharmacology/Templates]]

== External links ==
* [http://www.whocc.no/atcddd Official ATC website], hosted by the WHO Collaborating Centre for Drug Statistics Methodology

[[Category:Drugs]]
[[Category:Classification systems]]

[[ca:Codi ATC]]
[[da:Anatomisk terapeutisk kemisk klassifikation]]
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[[fr:Classification anatomique, thérapeutique et chimique]]
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[[id:Sistem Klasifikasi Kimiawi Terapeutik Anatomis]]
[[it:Anatomica Terapeutica Chimica]]
[[hu:Anatómiai, gyógyászati és kémiai osztályozási rendszer]]
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[[ja:解剖治療化学分類法]]
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[[pl:Klasyfikacja anatomiczno-terapeutyczno-chemiczna]]
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[[ru:Анатомо-терапевтическо-химическая классификация]]
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[[fi:Anatomis-terapeuttis-kemiallinen lääkeluokitus]]
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[[uk:Анатомічна терапевтична хімічна класифікація]]
[[zh:解剖学治疗学及化学分类系统]]