Assertion A: There is decreased effect of a drug when it is taken repeatedly.
Reason R: Conditioned compensatory response is not triggered when drug is taken in usual circumstances.
In the light of the above statements, choose the most appropriate answer from the options given below:
This section examines Assertion A and Reason R regarding drug effects.
Assertion A states that the effect of a drug decreases with repeated administration. This phenomenon is known as drug tolerance. Drug tolerance occurs when the body adapts to the drug, requiring a higher dose to achieve the same effect, or resulting in a diminished effect with the usual dose. This adaptation is a well-documented pharmacological principle.
Therefore, Assertion A is correct.
Reason R claims that a conditioned compensatory response is not triggered when a drug is taken in usual circumstances. Conditioned compensatory responses are a key mechanism contributing to drug tolerance. These responses are often elicited by environmental cues (e.g., the place where the drug is usually taken, the ritual of taking it) that become associated with the drug's effects.
When these usual circumstances (and associated cues) are present, the body activates compensatory mechanisms that oppose the drug's effects, thereby contributing to tolerance. The statement that these responses are *not* triggered in usual circumstances is contrary to established understanding of conditioned drug responses.
Therefore, Reason R is incorrect.
Based on the analysis:
This aligns with the option stating that A is correct but R is not correct.