Which of the following terms refers to decreased drug response after repeated use?

The term that refers to a decreased drug response after repeated use is tachyphylaxis. This phenomenon occurs when there is a rapid decrease in response to a drug following its administration. It can happen after just a few doses, reflecting a quick onset of tolerance or receptor desensitization. This is particularly important in the context of local anesthetics where repeated administration to the same tissue can result in significantly diminished effects.

While tolerance is often confused with tachyphylaxis, it refers to a more gradual decrease in drug response that develops over time and with continual use of a medication. This difference in time frame and mechanism is key in distinguishing the two concepts.

Addiction and dependence describe behavioral and physiological responses to a drug. Addiction involves a compulsive craving and sought-after use despite harmful consequences, while dependence refers to the physiological adaptations that occur due to the chronic use of a drug, leading to withdrawal symptoms upon cessation. Neither of these terms accurately captures the rapid decrease in response characteristic of tachyphylaxis.