Registered Practical Nurse (RPN) Practice Test

Which term encompasses the therapeutic effect produced by receptor activation?

1. Intrinsic activity

2. Synergism

3. Affinity

4. Efficacy

The correct answer is: Efficacy

The term that encompasses the therapeutic effect produced by receptor activation is efficacy. Efficacy refers to the ability of a drug to produce a desired therapeutic effect once it binds to its target receptor. It highlights how effectively a drug can activate the receptor leading to a response, which is essential in determining the drug’s overall effectiveness in clinical use. In contrast, intrinsic activity specifically pertains to the degree to which a drug activates a receptor upon binding, affecting how much response it produces. While intrinsic activity is an important concept, efficacy reflects not only the activation of receptors but also the resulting therapeutic outcomes. Synergism describes the interaction between two or more substances where their combined effect exceeds the sum of their individual effects; it’s about interactions rather than the action of a single agent at receptors. Affinity relates to how well a drug binds to its receptor, but this does not directly equate to the therapeutic effect produced once the receptor is activated. Therefore, efficacy is the most appropriate term to describe the therapeutic effects resulting from receptor activation.