A pharmacological paradox may a neutral antagonist shift an agonist concentration-response curve to the left
It is generally accepted that the presence of a competitive antagonist shifts an agonist concentration-response curve to the right. However, this may not always be the case The concentration-response curve of an inverse receptor agonist may be shifted to the left by a neutral antagonist a condition, which can be hypothetically explained by the assumption of both negative cooperativity of dimeric receptors plus a receptor reserve.