Which term describes a drug response that is all-or-none and typically plotted as the fraction of a population showing an effect?

Which term describes a drug response that is all-or-none and typically plotted as the fraction of a population showing an effect?

• A. A graded response
• B. A quantal response
• C. A pharmacokinetic response
• D. A therapeutic response

Answer: (B)

Quantal response describes an all-or-none outcome across individuals. In this approach, each subject either shows the drug effect or not at a given dose, and the data are plotted as the fraction of the population that exhibits the effect. This creates a sigmoidal dose–response curve and lets you determine population-level metrics like the ED50. This differs from a graded response, which measures the magnitude of effect within individuals on a continuous scale. The other terms don’t capture the binary, population-wide nature of the data.

Quantal response describes an all-or-none outcome across individuals. In this approach, each subject either shows the drug effect or not at a given dose, and the data are plotted as the fraction of the population that exhibits the effect. This creates a sigmoidal dose–response curve and lets you determine population-level metrics like the ED50. This differs from a graded response, which measures the magnitude of effect within individuals on a continuous scale. The other terms don’t capture the binary, population-wide nature of the data.