What is an antagonist in pharmacology?

In pharmacology, an antagonist is defined as a substance that blocks or interferes with the action of another drug or naturally occurring substance in the body. Specifically, antagonists bind to receptors and inhibit or dampen the biological response that would normally be triggered by the binding of an agonist (which is a substance that activates a receptor). This can be critical in therapeutic settings where it is necessary to negate the effects of an unwanted action, such as reversing the effects of an overdose of an agonist.

Understanding antagonism is essential for a range of pharmacological applications, including managing conditions like high blood pressure, where an antagonist might block receptors that promote vasodilation, thereby controlling blood pressure levels. This fundamental role of antagonists in the body underscores their importance in drug therapies and clinical practice.