<prompt> A drug that binds to a receptor at a site distinct from the active site and reduces the affinity of the receptor for the endogenous ligand is a:Competitive antagonistPaial antagonistInverse agonistAllosteric antagonist  <response>: A drug that binds to a receptor at a site distinct from the active site allosteric or non-agonist site and reduces the affinity of the receptor for the endogenous ligand is termed as allosteric inhibitor. Allosteric inhibition is a form of non-competitive antagonism Allosteric antagonism. Allosteric Modulator: An allosteric modulator is a drug that binds to a receptor at a site distinct from the active site and induces a conformational change in the receptor, which alters the affinity of the receptor for the endogenous ligand. Positive allosteric modulators increase the affinity, whilst negative allosteric modulators decrease the affinity. Ref: Katzung 14th edition Pgno: 24 