Which term describes compounds that elicit a maximal response following receptor occupation and activation?

Which term describes compounds that elicit a maximal response following receptor occupation and activation?

• A. Compounds that elicit a maximal response following receptor occupation and activation.
• B. Compounds that prevent receptor activation.
• C. Compounds that elicit no response.
• D. Compounds that only partially activate.

Answer: (A)

The key idea is efficacy—the ability of a drug to activate a receptor and produce a response. A compound that, after binding and activating the receptor, can drive the system to the maximal possible response has high intrinsic efficacy, meaning it’s a full agonist. It yields the entire, maximum effect when receptors are occupied. This distinguishes it from partial agonists, which only produce a fraction of the maximal response even with full receptor occupancy, and from antagonists or neutral ligands, which block activation or produce no effect.

The key idea is efficacy—the ability of a drug to activate a receptor and produce a response. A compound that, after binding and activating the receptor, can drive the system to the maximal possible response has high intrinsic efficacy, meaning it’s a full agonist. It yields the entire, maximum effect when receptors are occupied. This distinguishes it from partial agonists, which only produce a fraction of the maximal response even with full receptor occupancy, and from antagonists or neutral ligands, which block activation or produce no effect.