What are the two types of desensitization?

What are the two types of desensitization?

• A. Tachyphylaxis and desensitization
• B. Tolerance and down-regulation
• C. Tolerance and tachyphylaxis
• D. Up-regulation and desensitization

Answer: (C)

Desensitization means the body responds less to a drug after repeated exposure. The two classic forms are tolerance and tachyphylaxis. Tolerance develops gradually over time; with repeated dosing, the same amount of drug produces a smaller effect, or you may need a higher dose to achieve the same response. This can reflect changes in how the body processes the drug or adaptive changes at the target, and it tends to unfold over days to weeks. Tachyphylaxis, on the other hand, is a rapid loss of response right after initial exposure, often within minutes to hours, even when the dose remains the same. It usually results from quick receptor desensitization or depletion of signaling mediators. While changes in receptor numbers (up-regulation or down-regulation) can contribute to desensitization, the standard classifications in this context are tolerance (slow, gradual) and tachyphylaxis (rapid).

Desensitization means the body responds less to a drug after repeated exposure. The two classic forms are tolerance and tachyphylaxis. Tolerance develops gradually over time; with repeated dosing, the same amount of drug produces a smaller effect, or you may need a higher dose to achieve the same response. This can reflect changes in how the body processes the drug or adaptive changes at the target, and it tends to unfold over days to weeks. Tachyphylaxis, on the other hand, is a rapid loss of response right after initial exposure, often within minutes to hours, even when the dose remains the same. It usually results from quick receptor desensitization or depletion of signaling mediators. While changes in receptor numbers (up-regulation or down-regulation) can contribute to desensitization, the standard classifications in this context are tolerance (slow, gradual) and tachyphylaxis (rapid).