What does substance specificity refer to?

Substance specificity refers to the capability of a drug to selectively target specific receptors. This characteristic is crucial in pharmacology because it determines how a drug interacts with the body, influencing its efficacy and safety. When a drug has high substance specificity, it produces its intended therapeutic effects while minimizing the likelihood of interacting with other, non-target receptors. This precision reduces the chance of side effects and enhances the overall therapeutic outcome.

The other concepts mentioned relate to different aspects of drug action. For example, the idea of acting on multiple targets is contrary to specificity, as it implies a broader interaction profile. Binding to any enzyme suggests a lack of specificity, which can lead to unintended consequences. Lastly, a narrow therapeutic window pertains to the safety of the drug rather than its specificity, highlighting the differences in how well a drug can target specific receptors without affecting others. Thus, the correct understanding of substance specificity focuses on selective action rather than broader or unfocused interactions.