In pharmacology, tolerance refers to

In pharmacology, tolerance refers to

• A. A desire to stop after repeated use.
• B. A reversible mood change after withdrawal.
• C. A decrease in the drug's effect requiring higher doses.
• D. A genetic predisposition independent of use.

Answer: (C)

Tolerance is a decreased responsiveness to a drug after repeated use, so more of the drug is needed to achieve the same effect. This can arise from changes in the body such as receptor desensitization or downregulation (pharmacodynamic tolerance) or from faster metabolism of the drug (pharmacokinetic tolerance). It’s distinct from withdrawal, which are symptoms that occur when stopping use, and from a predisposition to use. So the idea that the drug’s effect diminishes with continued use, requiring higher doses, best captures tolerance.

Tolerance is a decreased responsiveness to a drug after repeated use, so more of the drug is needed to achieve the same effect. This can arise from changes in the body such as receptor desensitization or downregulation (pharmacodynamic tolerance) or from faster metabolism of the drug (pharmacokinetic tolerance). It’s distinct from withdrawal, which are symptoms that occur when stopping use, and from a predisposition to use. So the idea that the drug’s effect diminishes with continued use, requiring higher doses, best captures tolerance.