Potency is best described as what?

Potency is best described as what?

• A. The maximal effect the drug can produce.
• B. The effect at a specific concentration; smaller EC50 indicates higher potency.
• C. The slope of the dose–response curve.
• D. The receptor occupancy at a given dose.

Answer: (B)

Potency describes how much drug is needed to produce a given level of effect. We quantify this with the EC50, the concentration that yields 50% of the maximal response. A smaller EC50 means you need less drug to reach that level, so the drug is more potent. This reflects where the dose–response curve sits along the concentration axis, not how big the maximum effect will be. The maximum effect (efficacy) is about how strong the response can be, regardless of dose, while the slope and receptor occupancy relate to how quickly responses rise and how many receptors are engaged, respectively. So potency is best described as the effect at a given concentration, with a smaller EC50 indicating higher potency.

Potency describes how much drug is needed to produce a given level of effect. We quantify this with the EC50, the concentration that yields 50% of the maximal response. A smaller EC50 means you need less drug to reach that level, so the drug is more potent. This reflects where the dose–response curve sits along the concentration axis, not how big the maximum effect will be. The maximum effect (efficacy) is about how strong the response can be, regardless of dose, while the slope and receptor occupancy relate to how quickly responses rise and how many receptors are engaged, respectively. So potency is best described as the effect at a given concentration, with a smaller EC50 indicating higher potency.