Drug class

A drug class is a set of medications that have similar chemical structures, the same mechanism of action (i.e., bind to the same biological target), a related mode of action, and/or are used to treat the same disease.

In several dominant drug classification systems, these four types of classifications form a hierarchy. For example, the fibrates are a chemical class of drugs (amphipathic carboxylic acids) that share the same mechanism of action (PPAR agonist), mode of action (reducing blood triglycerides), and are used to prevent and to treat the same disease (atherosclerosis). Conversely not all PPAR agonists are fibrates, not all triglyceride lowering agents are PPAR agonists, and not all drugs that are used to treat atherosclerosis are triglyceride lowering agents.

The most widely used drug classification system is the Anatomical Therapeutic Chemical Classification System (ATC). The Systematized Nomenclature of Medicine (SNOMED) also includes a section devoted to drug classification.

Examples of drug classes that are based on chemical structures include:

Drug classes that share a common molecular mechanism of action by modulating the activity of a specific biological target. The definition of a mechanism of action also includes the type of activity at that biological target. For receptors, these activities include agonist, antagonist, inverse agonist, or modulator. Enzyme target mechanisms include activator or inhibitor. Ion channel modulators include opener or blocker. The following are specific examples of drug classes whose definition is based on a specific mechanism of action:

...
Wikipedia