If a drug has high potency, what does this imply about the required dose to achieve the desired effect?

• A. Larger dose is required
• B. The duration of action is long
• C. A smaller dose is sufficient
• D. The drug is more likely to cause withdrawal

Answer: (C)

Potency describes how much of a drug is needed to produce a given effect. A highly potent drug reaches the desired effect with a much smaller amount, so a smaller dose suffices to achieve the same outcome. This concept is about the dose-response relationship at the receptor level and is different from how long the drug lasts or whether it can cause withdrawal, which depend on pharmacokinetics and dependence potential. For example, fentanyl achieves the same effect as morphine at far smaller doses. So high potency means a smaller dose is enough.