Potency is defined as what?

Potency is defined as what?

• A. The amount of drug needed to produce an effect
• B. Potency
• C. The speed of onset
• D. The duration of action

Answer: (A)

Potency refers to how much of a drug is needed to produce a given level of effect. If a drug achieves the same effect at a smaller dose, it is more potent. This idea is often shown on dose–response curves, where a leftward shift means greater potency because the target effect is reached with less drug. The exact dose that yields a defined effect, like 50% of the maximal response (ED50 or EC50), is a common way to quantify potency. Potency is distinct from how fast a drug acts (onset) or how long the effect lasts (duration); those are separate properties of a drug.

Potency refers to how much of a drug is needed to produce a given level of effect. If a drug achieves the same effect at a smaller dose, it is more potent. This idea is often shown on dose–response curves, where a leftward shift means greater potency because the target effect is reached with less drug. The exact dose that yields a defined effect, like 50% of the maximal response (ED50 or EC50), is a common way to quantify potency. Potency is distinct from how fast a drug acts (onset) or how long the effect lasts (duration); those are separate properties of a drug.