In pharmacology, what does 'potency' refer to?

Potency in pharmacology specifically refers to the strength or concentration of a drug relative to its effect. This concept means that a more potent drug will produce a desired therapeutic effect at a lower dose compared to a less potent drug. For instance, if Drug A requires a smaller dose to achieve a similar therapeutic effect as Drug B, Drug A is considered more potent. Understanding potency is crucial for prescribing and dosing medications effectively, ensuring that patients receive the optimal therapeutic benefit while minimizing side effects and risk of toxicity.

The other concepts mentioned in the options, such as the range of therapeutic effects, duration of action, or the overall safety profile, pertain to different pharmacological properties and do not define potency. While these factors are important for assessing a drug's overall effectiveness and safety, potency specifically relates to the strength of the drug and its effect at a given concentration or dose.