Which term describes a drug that binds to a receptor but has limited response?

The term that describes a drug that binds to a receptor but has limited response is an agonist-antagonist. This type of drug has properties of both agonists and antagonists, meaning it can activate a receptor to a certain degree while also blocking or limiting the effects of full agonists at the same receptor. This partial activation is what leads to a limited or submaximal response, even though the drug successfully engages with the receptor.

In contrast, a full agonist would lead to a maximum response by fully activating the receptor, and an antagonist would block the receptor entirely, preventing any response. An inhibitor usually refers to a substance that decreases the activity of an enzyme or receptor but does not specifically describe the response level it induces when binding to a receptor. Understanding these concepts is crucial for grasping pharmacological principles and the way different types of drugs affect the body.