Is there a relationship between potency and efficacy?

In pharmacology, efficacy and potency are distinct concepts that describe different properties of a drug's action.

Efficacy refers to the maximum effect a drug can produce, regardless of the dose. It indicates how well a drug works in achieving the desired therapeutic outcome. A drug with high efficacy can produce a significant response even at relatively low concentrations.

Potency, on the other hand, refers to the amount of drug needed to produce a defined effect. A more potent drug will evoke a response at lower doses compared to a less potent drug. However, potency does not describe how robust or powerful that response is; it only addresses the quantity of the drug required to elicit a certain percentage of the efficacy.

Thus, the statement about the relationship between potency and efficacy being false is accurate. While a drug can be potent yet have low efficacy (requiring little drug to produce a small effect), it can also be less potent but have high efficacy (requiring more drug to achieve its maximum effect). These elements operate independently, emphasizing that a potent drug may not necessarily accomplish a significant therapeutic effect, and vice versa.