What do antagonist drugs ultimately produce at a receptor site?

Antagonist drugs specifically bind to receptor sites but do not activate them. Instead, they block or inhibit the action of agonists, which are substances that naturally bind to those receptors and produce a physiological response. By occupying the receptor sites, antagonists prevent agonists from attaching, thus leading to a decrease or complete blockade of the normal receptor-mediated effects, effectively producing the opposite effect of what would occur if the receptor were stimulated by an agonist.

This mechanism makes antagonists essential in various therapeutic contexts, as they can reverse or counteract unwanted physiological effects caused by stimulants or other activating substances. In clinical practice, understanding the role of antagonists is crucial for managing conditions like hypertension or allergies, where receptor blockage can lead to significant symptom relief.