General Pharmacology

Mechanism of Action MoA

TREtki Mekanizması
Also known as:Mechanism of drug action

The specific biochemical interaction through which a drug produces its pharmacological effect, usually binding to a defined molecular target such as a receptor, enzyme, ion channel or transporter.

In depth

The four major classes of drug target are receptors, enzymes, ion channels and transporters; a smaller group of drugs acts through physicochemical mechanisms without a specific target (osmotic diuretics, antacids, chelating agents). A full description of mechanism links the molecular event, for example irreversible acetylation of cyclo-oxygenase by aspirin, to the downstream cellular, organ-level and clinical effects.

Mechanism is distinguished from mode of action, which describes the resulting functional or anatomical change. Knowing the mechanism helps predict class effects, adverse reactions, pharmacodynamic interactions and rational combinations; for some long-established drugs it is still incompletely understood.

Clinical pearl

Two drugs sharing the same mechanism (for example, two NSAIDs) seldom add benefit but do add toxicity, whereas combining complementary mechanisms, as in hypertension or tuberculosis, is a standard strategy.

Example drugs

aspirin
TRIn Turkish

Etki Mekanizması

Bir ilacın farmakolojik etkisini oluşturduğu özgül biyokimyasal etkileşimdir; bu etkileşim genellikle reseptör, enzim, iyon kanalı veya taşıyıcı gibi tanımlı bir moleküler hedefe bağlanma şeklindedir.

İlaç hedeflerinin dört ana sınıfı reseptörler, enzimler, iyon kanalları ve taşıyıcılardır; daha küçük bir ilaç grubu ise özgül bir hedef olmaksızın fizikokimyasal mekanizmalarla etki eder (ozmotik diüretikler, antasitler, şelatör ajanlar). Mekanizmanın tam tanımı, moleküler olayı (örneğin aspirinin siklooksijenazı geri dönüşümsüz olarak asetillemesi) hücresel, organ düzeyindeki ve klinik sonuçlara bağlar.

Etki mekanizması, ortaya çıkan işlevsel veya anatomik değişikliği tanımlayan etki biçiminden (mode of action) ayrılır. Mekanizmanın bilinmesi sınıf etkilerini, advers reaksiyonları, farmakodinamik etkileşimleri ve akılcı kombinasyonları öngörmeye yardımcı olur; uzun süredir kullanılan bazı ilaçlarda mekanizma hâlâ tam olarak aydınlatılamamıştır.

Aynı mekanizmayla etki eden iki ilacın (örneğin iki NSAİİ) birlikte kullanımı yarardan çok toksisiteyi artırır; hipertansiyon veya tüberkülozda olduğu gibi birbirini tamamlayan mekanizmaların birleştirilmesi ise standart bir stratejidir.

Diğer adları:İlaç etki mekanizması
Updated 24.09.2026 0 views Educational reference — verify against current sources before clinical use.

Read next

PharmacodynamicsFarmakodinamik

The branch of pharmacology that studies what a drug does to the body: the biochemical and physiological effects of drugs, their mechanisms of action and the relationship between drug concentration and response.

 ReceptorReseptör

A macromolecule, usually a protein, to which a drug or endogenous ligand binds specifically and thereby initiates a change in cell function that produces a biological response.

 Enzyme InhibitionEnzim İnhibisyonu

A reduction in the activity of a drug-metabolizing enzyme by a co-administered drug or other substance, which lowers the clearance of drugs dependent on that enzyme and raises their concentrations.

 Drug Transporterİlaç Taşıyıcısı

A membrane protein that moves drugs across cell membranes, either into cells (uptake) or out of them (efflux), and thereby influences absorption, distribution and elimination.

 SelectivitySeçicilik

The degree to which a drug acts on a particular target (receptor subtype, enzyme or tissue) rather than on others, usually expressed as the ratio of its affinities or potencies at different targets.

 Pharmacodynamic InteractionFarmakodinamik Etkileşim

An interaction in which one drug modifies the response to another at the same or related receptors, physiological systems or pathways, independently of any change in plasma concentrations.