Wirkort

Wirkort is the specific location in the body where a drug or other active substance produces its pharmacological effect. In pharmacology and toxicology, the Wirkort is the molecular or cellular target—such as a receptor, enzyme, ion channel, or transporter—through which the substance initiates its therapeutic or toxic action. The Wirkort can be located in a particular tissue or cell type, and a drug may act on multiple Wirkorte.

Examples include receptor targets like beta-adrenergic receptors for beta-blockers; enzymes like cyclooxygenases for NSAIDs; ion channels such as voltage-gated calcium channels for certain antihypertensives; and transporters such as SERT for selective serotonin reuptake inhibitors. Sometimes the Wirkort is an entire organ system or a protein complex rather than a single molecule.

Wirkort is distinct from the Wirkmechanismus (mechanism of action). The Wirkort is the actual target location; the mechanism describes how binding or modulation at the target leads to downstream effects. A drug can have a primary Wirkort and multiple secondary targets, influencing efficacy and side effects.

Knowledge of Wirkorte supports drug development, dosing, and safety assessment, as tissue distribution and target expression determine selectivity. Identification methods include binding assays, pharmacological antagonism, genetic knockout models, and imaging techniques. Variation in Wirkort expression among individuals can contribute to differences in drug response.