A nurse is preparing to administer a medication and learns that it is a nonselective agonist drug. What does the nurse understand about this drug?

A. This describes a nonselective antagonist, which blocks multiple types of receptors to reduce activity across several physiological systems. While it affects many processes, it does not activate receptors—it prevents their activation. B. This describes a selective agonist, which targets one specific receptor type to produce a desired therapeutic effect in a single physiologic system. For example, a beta-1 selective agonist primarily affects the heart without significantly influencing other organs. C. A nonselective agonist directly activates multiple receptor types. Because it is nonselective, it does not differentiate between different receptor subtypes, so it can trigger a range of physiological effects in multiple organ systems. For instance, epinephrine is a nonselective agonist because it activates alpha and beta adrenergic receptors, leading to increased heart rate, bronchodilation, vasoconstriction, and other systemic effects. While this broad action can be therapeutically beneficial (e.g., in anaphylaxis), it also increases the potential for side effects such as hypertension, tachycardia, or arrhythmias. D. This describes a selective antagonist, which blocks a single receptor type to limit a specific physiologic process. An example is a beta-1 selective blocker, which reduces heart rate without significant effect on other organ systems.