Supersensitivity (the opposite of tachyphylaxis) is an abnormal exaggerated response to stimulation which occurs after a series of administrations. After the first administrations of a drug, a normal response is displayed as shown in the upper graphic. However, after repeated administrations the response in much higher while the same dose is administered.
Already at low doses the patient displays a high response. Supersensitivity is important in CNS inhibiting drug therapy. When long-term antagonist therapy is suddenly stopped, supersensitive reactions can occur.