What are drugs called that bind to receptors but do not activate them?

Drugs that bind to receptors but do not activate them are known as antagonists. Antagonists are designed to block or inhibit the action of other substances, typically natural neurotransmitters or hormones, that do activate the receptors. By occupying the receptor sites, antagonists prevent the agonists (the active substances) from binding and exerting their effects, thereby modulating the physiological responses in the body.

For instance, in the case of beta-blockers, which are a class of antagonists, these medications attach to beta-adrenergic receptors and prevent adrenaline from stimulating them, effectively reducing heart rate and blood pressure. This characteristic makes antagonists valuable in various therapeutic situations, such as managing hypertension or treating anxiety disorders.

Understanding the role of antagonists is crucial in pharmacology, as they can be used to counteract the effects of overactive systems or block undesired responses in the body.