NAPNES Pharmacology Exam Prep practice questions and answers 2026. Tap an option to test yourself — you'll see the correct answer and a plain-English explanation for every question. Free, no login.
Q21Which pharmacokinetic process describes the movement of a drug from the site of administration into the bloodstream?
✓ Correct answer: D. Absorption
Absorption is the process by which a drug moves from its site of administration (such as the GI tract, muscle, or skin) into the systemic circulation. This is the first phase of pharmacokinetics.
Q22A drug with a half-life of 6 hours is administered at 0800. Approximately what percentage of the original dose remains in the body at 2000?
✓ Correct answer: C. 25%
After one half-life (6 hours, at 1400), 50% remains. After two half-lives (12 hours, at 2000), 25% of the original dose remains. Each half-life reduces the drug concentration by half.
Q23The therapeutic index of a drug is best defined as the relationship between which two factors?
✓ Correct answer: B. The toxic dose and the therapeutic dose
The therapeutic index is the ratio between the dose that produces toxicity and the dose that produces a therapeutic effect. A wider therapeutic index indicates a safer drug with a larger margin between effective and toxic doses.
Q24Which term describes the percentage of an administered drug dose that reaches systemic circulation in unchanged form?
✓ Correct answer: A. Bioavailability
Bioavailability refers to the fraction of an administered dose that reaches the systemic circulation unchanged and is available to produce its therapeutic effect. Intravenous drugs have 100% bioavailability, while oral drugs may have lower bioavailability due to first-pass metabolism.
Q25A drug that binds to a receptor but does not activate it and prevents other substances from binding is classified as which of the following?
✓ Correct answer: D. Antagonist
An antagonist binds to a receptor without activating it and blocks the binding of agonists or endogenous ligands, thereby preventing receptor activation and the associated biological response.
Q26The first-pass effect primarily affects drugs administered by which route?
✓ Correct answer: C. Oral
The first-pass effect occurs when oral drugs are absorbed from the GI tract into the portal circulation and metabolized by the liver before reaching systemic circulation. This can significantly reduce the bioavailability of orally administered drugs.
Q27Which pharmacokinetic process involves the reversible transfer of a drug between body compartments such as blood, tissues, and organs?
✓ Correct answer: A. Distribution
Distribution is the process by which a drug is transported from the bloodstream to various tissues and organs throughout the body. Factors affecting distribution include blood flow, protein binding, and tissue permeability.
Q28A patient is receiving a drug with a narrow therapeutic index. What is the primary nursing implication for this patient?
✓ Correct answer: C. Close monitoring is required because the margin between therapeutic and toxic doses is small
A narrow therapeutic index means there is a small margin between therapeutic and toxic doses. Close monitoring of drug levels and patient response is essential to prevent toxicity while maintaining therapeutic effectiveness.
Q29A patient receiving vancomycin infusion develops flushing, pruritus, and hypotension. Which adverse reaction should the nurse suspect?
✓ Correct answer: B. Red man syndrome
Red man syndrome is a vancomycin-related adverse effect characterized by flushing, pruritus, hypotension, and sometimes chest pain. It occurs due to histamine release when the drug is infused too rapidly.
Q30A patient is prescribed warfarin therapy. Which laboratory value is most important for the nurse to monitor?
✓ Correct answer: D. INR
INR (International Normalized Ratio) is the laboratory value used to monitor warfarin effectiveness and adjust dosing. Therapeutic range is typically 2-3 for most indications.
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Theory