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1. A patient with asthma is prescribed a beta2-agonist. Which

pharmacodynamic principle explains the bronchodilation effect?

 A. Receptor theory

 B. Drug-receptor interaction

 C. Dose-response relationship

 D. Drug metabolism

 Answer: B. Drug-receptor interaction

 Rationale: Beta2-agonists work by binding to beta2-adrenergic receptors

on the smooth muscle cells of the airways, leading to bronchodilation.

2. Which term describes the magnitude of maximal response that can be

produced from a particular drug?

 A. Potency

 B. Efficacy

 C. Therapeutic index

 D. Bioavailability

 Answer: B. Efficacy

 Rationale: Efficacy refers to the inherent ability of a drug to produce a

maximal response.

3. What does the term 'agonist' refer to in pharmacology?

 A. A drug that blocks receptor activity

 B. A drug that enhances receptor activity

 C. A drug that has no effect on receptor activity

 D. A drug that reduces the metabolism of another drug

 Answer: B. A drug that enhances receptor activity

 Rationale: An agonist is a substance that binds to a receptor and

activates it, producing a physiological response.

4. In the context of pharmacodynamics, what does 'affinity' refer to?

 A. The rate at which a drug is eliminated from the body

 B. The strength of binding between a drug and its receptor

 C. The ability of a drug to pass through cell membranes

 D. The degree to which a drug causes side effects

 Answer: B. The strength of binding between a drug and its receptor

 Rationale: Affinity is the measure of how tightly a drug binds to its

receptor.