What is ATC classification?

The Anatomical Therapeutic Chemical (ATC) classification system organizes therapeutically active substances (drugs) according to their anatomical/pharmacological use. The ATC classification is controlled by the WHO Collaborating Centre for Drug Statistics Methodology. The molecular definitions of small molecule drugs, as classified by the ATC are included in this browser tree. The mapping of ATC classification is based on information derived from DrugBank. Note: the ATC drug names are listed in this classification only when corresponding molecular definitions are available in the chemical component and/or BIRD dictionaries.

Why browse by ATC classification?

The ATC classification provides information about the organ or system on which active ingredients of a drug acts and their therapeutic, pharmacological, and chemical properties. Browsing through this tree can help find drugs that are related in structure and or function. Exploring the complexes structures of a drug of interest can help identify targets and off-target proteins for one specific or a class of drugs.

How to use the ATC Browser?

Users can click on the browser tree branches to navigate to the drug or drug class of interest. Alternatively you can search for drugs by typing in the name or ATC ID in the search box on the page. After locating the drug/class in the browser, users can view the number of molecular definitions that match the query by clicking on the hyperlinked numbers listed next to the drug class name.


Structures containing Sitagliptin, a common drug used to treat diabetes, can be identified as follows:

  • Browse the tree for “Alimentary Tract and Metabolism Drugs >> Drugs Used in Diabetes >> Blood Glucose Lowering Drugs, Excl. Insulins >> Dipeptidyl peptidase 4 (DPP-4) inhibitors for blood glucose lowering’ OR
  • Search by typing the drug name (Sitagliptin) or ATC classification (A10BH01) in the search box on the page and select from the options provided.

Once you see the results list, scroll up to the Advanced Query Builder options and select "Structures" from the Return options pull down menu and click on the green magnifying lens (search icon) at the bottom right corner of this section. This will provide a list of the structures in the archive with this drug (molecular definition).

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Last updated: 6/25/2024