Comprehensive Nursing Pharmacology Q 287

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When a drug binds to a receptor to produce a pharmacologic effect, the drug may be called a(n):

  

     A. Antagonist

     B. Agonist

     C. Blocker

     D. Accelerator

    

    

Correct Answer: B. Agonist

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An agonist is the action described in the stem. Agonist and blocker are synonymous. An agonist is a drug that activates certain receptors in the brain. An agonist is a medication that mimics the action of the signal ligand by binding to and activating a receptor.

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Option A: An interaction between two or more drugs that have opposite effects on the body. Drug antagonism may block or reduce the effectiveness of one or more of the drugs.

Option C: Drug antagonism, in contrast, is often undesirable, but could be useful in selecting against drug-resistant mutations. Yeh et al. categorized drug antagonism into two categories: antagonistic buffering and antagonistic suppression. In the case of antagonistic suppression, one drug suppresses the action of the other, producing a “hyper-antagonism” with a maximum combination index larger than 2.

Option D: There is no such action described in drug nomenclature. Drug-drug interactions occur when two or more drugs react with each other. This drug-drug interaction may cause the client to experience an unexpected side effect. For example, mixing a drug taken to help sleep (a sedative) and a drug taken for allergies (an antihistamine) can slow the reactions and make driving a car or operating machinery dangerous.

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