A drug that binds to a receptor at a site distinct from the active site and alters the affinity of the receptor for the endogenous ligand is a:-

* Allosteric modulator that binds to a receptor at a site distinct from the active site and alters the affinity of the receptor for the endogenous ligand. * Competitive antagonist binds to the same site as that of agonist, produces surmountable effect i.e. effect of antagonist can be overcome by increasing concentration of agonist. * Inverse agonist and paial agonist also bind to the same site as that of the agonist.