Which term describes a state of functional adaptation to a drug in which the presence of a foreign chemical becomes normal and necessary, and the absence would present an abnormal state?

Which term describes a state of functional adaptation to a drug in which the presence of a foreign chemical becomes normal and necessary, and the absence would present an abnormal state?

• A. Pharmacodynamic tolerance
• B. Metabolic tolerance
• C. Intoxication
• D. Physical dependence

Answer: (D)

The concept being tested is physical dependence. This term describes a state where the body undergoes functional adaptation to a drug so that its ongoing presence becomes normal and necessary for the person to feel or function normally. If the drug is suddenly stopped, withdrawal symptoms or an abnormal state arise because the body's adjusted physiology now relies on the substance. This differs from pharmacodynamic tolerance, where the body becomes less responsive to the drug over time and higher doses are needed to achieve the same effect, but stopping the drug doesn’t inherently produce a withdrawal state tied to an adaptation for normal functioning. Metabolic tolerance involves faster metabolism of the drug, which changes how much is needed to achieve effects but again isn’t centered on withdrawal from a normal state. Intoxication refers to the acute, current effects of the drug while it’s present, not the adaptation and withdrawal pattern described here.

The concept being tested is physical dependence. This term describes a state where the body undergoes functional adaptation to a drug so that its ongoing presence becomes normal and necessary for the person to feel or function normally. If the drug is suddenly stopped, withdrawal symptoms or an abnormal state arise because the body's adjusted physiology now relies on the substance.

This differs from pharmacodynamic tolerance, where the body becomes less responsive to the drug over time and higher doses are needed to achieve the same effect, but stopping the drug doesn’t inherently produce a withdrawal state tied to an adaptation for normal functioning. Metabolic tolerance involves faster metabolism of the drug, which changes how much is needed to achieve effects but again isn’t centered on withdrawal from a normal state. Intoxication refers to the acute, current effects of the drug while it’s present, not the adaptation and withdrawal pattern described here.