can you give a few examples?
Alpha blockers, beta blockers, and calcium channel blockers
Receptor antagonist
They are sometimes called blockers; examples include alpha blockers, beta blockers, and calcium channel blockers.
a substance that binds to a receptor and has an agonistic or antagonistic effect is called Receptor antagonist
wiki:20193985
Receptor antagonist [SEP] Introduction
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in natural works of receptor protein. They are sometimes called blockers; examples include alpha blockers, beta blockers, and calcium channel blockers. In pharmacology, antagonists have affinity but no efficacy for their cognate receptors, and binding will disrupt the interaction and inhibit the function of an agonist or inverse agonist at receptors. Antagonists mediate their effects by binding to the active site or to the allosteric site on a receptor, or they may interact at unique binding sites not normally involved in the biological regulation of the receptor's activity.