Which of the following terms best describes a drug that blocks the action of adrenaline at its receptors by occupying those receptors without activating them: (A) Pharmacological antagonist, (B) Non competitive antagonist, (C) Psychological antagonist, (D) Chemical antagonist
Answer is A. Ref-Katzung 10/e p16 pharmacological antagonism. the relationship between drugs in which an antagonist inhibits the activity of an agonist by reacting with the receptor or other pa of the effector mechanism.