Graded dose responses are best described as:

• A. A continuous scale, related to intensity of effect (reduction in blood pressure).
• B. All-or-none pharmacologic effect, relates dose to frequency of effect.
• C. A binary outcome observed across individuals.
• D. A stepwise relationship with distinct plateaus.

Answer: (B)

Graded dose-response curves depict how the magnitude of a drug’s effect changes smoothly as the dose is increased within the same individual. The key idea is a continuous relationship: higher doses produce progressively greater (or lesser, depending on the effect) responses, such as a gradual increase in blood pressure reduction. This contrasts with a population-wide, all-or-none description where the focus is on whether the effect occurs or not in each person, and the curve reflects the proportion of individuals who respond at each dose. It also doesn’t fit a stepwise, plateaued pattern, which implies discrete jumps rather than a smooth change. So the best description is a continuous scale relating dose to the intensity of the effect.