Drug class/ja

薬物クラス（drug class）とは、類似した化学構造を持ち、同じ作用機序(mechanism of action)（すなわち、同じ生物学的標的に結合する）を持ち、関連した作用機序(mode of action)を持ち、および/または同じ疾患の治療に用いられる医薬品およびその他の化合物の集合である。

いくつかの支配的な薬物分類システムでは、これら4種類の分類が階層を形成している。例えば、フィブラート類は、同じ作用機序（PPARアゴニスト）と作用機序（血中トリグリセリドの低下）を共有し、同じ疾患（アテローム性動脈硬化症）の予防と治療に使用される薬物（両親媒性カルボン酸）の化学的分類である。逆に、すべてのPPARアゴニストがフィブラート系薬剤であるわけではなく、すべてのトリグリセリド低下薬がPPARアゴニストであるわけでもなく、動脈硬化の治療に使用されるすべての薬物がトリグリセリド低下薬であるわけでもない。

A drug class is typically defined by a prototype drug, the most important, and typically the first developed drug within the class, used as a reference for comparison.

List of drugs classes: [1]

Comprehensive Systems

• Anatomical Therapeutic Chemical Classification System (ATC) - most widely used. Combines classification by organ system and therapeutic, pharmacological, and chemical properties.
• Systematized Nomenclature of Medicine (SNOMED) - includes a section devoted to drug classification

Chemical class

This type of categorisation of drugs is from a chemical perspective and categorises them by their chemical structure. Examples of drug classes that are based on chemical structures include:

• β-lactam antibiotic
• Benzodiazepine
• Cardiac glycoside
• Fibrate
• Thiazide diuretic
• Steroid
• Triptan

Mechanism of action

This type of categorisation is from a pharmacological perspective and categorises them by their biological target. Drug classes that share a common molecular mechanism of action modulate 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:

• 5-Alpha-reductase inhibitor
• Angiotensin II receptor antagonist
• ACE inhibitor
• Alpha-adrenergic agonist
• Beta blocker
• Cholinergic
• Dopaminergic
• GABAergic
• Incretin mimetic
• Nonsteroidal anti-inflammatory drug − cyclooxygenase inhibitor
• Proton-pump inhibitor
• Renin inhibitor
• Selective glucocorticoid receptor modulator
• Serotonergic
• Statin – HMG-CoA reductase inhibitor

Mode of action

This type of categorisation of drugs is from a biological perspective and categorises them by the anatomical or functional change they induce. Drug classes that are defined by common modes of action (i.e. the functional or anatomical change they induce) include:

• Antifungals
• Antimicrobials
• Antithrombotics
• Bronchodilator
• Chronotrope (positive or negative)
• Decongestant
• Diuretic or Antidiuretic
• Inotrope (positive or negative)

Therapeutic class

This type of categorisation of drugs is from a medical perspective and categorises them by the pathology they are used to treat. Drug classes that are defined by their therapeutic use (the pathology they are intended to treat) include:

• Analgesics
• Antibiotic
• Anticoagulant
• Antidepressant
• Anticancer
• Antidiabetic
• Antiepileptic
• Antipsychotic
• Antispasmodic
• Antiviral
• Cardiovascular
• Depressant
• Sedative
• Stimulant

Amalgamated classes

Some drug classes have been amalgamated from these three principles to meet practical needs. The class of nonsteroidal anti-inflammatory drugs (NSAIDs) is one such example. Strictly speaking, and also historically, the wider class of anti-inflammatory drugs also comprises steroidal anti-inflammatory drugs. These drugs were in fact the predominant anti-inflammatories during the decade leading up to the introduction of the term "nonsteroidal anti-inflammatory drugs." Because of the disastrous reputation that the corticosteroids had got in the 1950s, the new term, which offered to signal that an anti-inflammatory drug was not a steroid, rapidly gained currency. The drug class of "nonsteroidal anti-inflammatory drugs" (NSAIDs) is thus composed by one element ("anti-inflammatory") that designates the mechanism of action, and one element ("nonsteroidal") that separates it from other drugs with that same mechanism of action. Similarly, one might argue that the class of disease-modifying anti-rheumatic drugs (DMARD) is composed by one element ("disease-modifying") that albeit vaguely designates a mechanism of action, and one element ("anti-rheumatic drug") that indicates its therapeutic use.

• Nonsteroidal anti-inflammatory drug (NSAID)
• Disease-modifying antirheumatic drug (DMARD)

Other systems of classification

Other systems of drug classification exist, for example the Biopharmaceutics Classification System which determines a drugs' attributes by solubility and intestinal permeability.

Legal classification

• For the UK legal classification, see Drugs controlled by the UK Misuse of Drugs Act
• For the US legal classification, see Controlled Substances Act § Schedules of controlled substances
• For the Canadian legal classification, see Controlled Drugs and Substances Act
• Pregnancy category is defined using a variety of systems by different jurisdictions

External links

• "Drug names and classes". PubMed Health. United States National Library of Medicine. Retrieved 2015-11-07.
• "Information by Drug Class". Drug Safety and Availability. United States Food and Drug Administration. Retrieved 2015-11-07.