Rationales | Pharmacology V1 (2026/2027 Edition)
Fortis College Nursing Pharmacology HESI Examination V1
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SECTION 1: Pharmacological Principles
Question 1
A nurse is reviewing pharmacokinetic principles with a nursing student. The student
asks which organ is primarily responsible for drug metabolism. Which response by the
nurse is most accurate?
A. Kidneys
B. Liver
C. Lungs
D. Intestines
Correct Answer: B
Rationale: The liver is the primary organ responsible for drug metabolism through
enzymatic biotransformation, primarily via the cytochrome P450 enzyme system. The
kidneys are the primary organ for drug excretion. The lungs excrete volatile substances
and gases. The intestines play a minor role in metabolism via intestinal enzymes and
gut flora, but the liver remains the principal metabolic organ.
Question 2
,A nurse is administering a medication with a narrow therapeutic index. Which statement
by the nurse indicates correct understanding of this concept?
A. "A narrow therapeutic index means there is a wide margin of safety between the
effective dose and the toxic dose."
B. "A narrow therapeutic index means the effective dose and toxic dose are very close,
requiring frequent monitoring of serum drug levels."
C. "A narrow therapeutic index indicates the drug is safe to administer without
monitoring."
D. "A narrow therapeutic index means the drug is always given in subtherapeutic doses."
Correct Answer: B
Rationale: A narrow therapeutic index (NTI) indicates that the difference between the
minimum effective concentration and the minimum toxic concentration is small. Drugs
with a narrow therapeutic index (e.g., digoxin, lithium, warfarin, phenytoin,
aminoglycosides) require frequent therapeutic drug monitoring to maintain serum levels
within the narrow therapeutic range and prevent toxicity. A wide therapeutic index
indicates a large margin of safety.
Question 3
A client is prescribed a medication that undergoes first-pass metabolism. The nurse
should recognize that first-pass metabolism primarily occurs in which location?
A. Stomach
B. Liver
C. Kidneys
D. Lungs
Correct Answer: B
,Rationale: First-pass metabolism (first-pass effect) occurs when a drug absorbed from
the gastrointestinal tract travels via the portal vein to the liver before entering the
systemic circulation. In the liver, a significant portion of the drug may be metabolized,
reducing the bioavailability of orally administered drugs. This explains why some drugs
(e.g., nitroglycerin, insulin) cannot be given orally and must be administered via
alternative routes to bypass first-pass metabolism.
Question 4
A nurse is reviewing a client's medication list and notes that the client is taking two
medications that both compete for the same metabolic pathway in the liver. Which
consequence should the nurse anticipate?
A. Decreased absorption of both medications
B. Increased plasma levels of one or both medications due to reduced metabolism
C. Increased excretion of both medications by the kidneys
D. Decreased distribution of both medications to target tissues
Correct Answer: B
Rationale: When two drugs compete for the same metabolic enzyme pathway (such as
cytochrome P450 isoenzymes), one drug may inhibit the metabolism of the other,
leading to increased plasma levels, prolonged half-life, and increased risk of adverse
effects or toxicity. This is a common mechanism of drug-drug interactions. The nurse
monitors for signs of toxicity and consults the pharmacist or provider regarding dose
adjustments or alternative medications.
Question 5
, A nurse is caring for a client who is receiving a drug that acts as an agonist at beta-1
adrenergic receptors. Which physiological effect should the nurse expect?
A. Bronchodilation and decreased airway resistance
B. Increased heart rate, increased myocardial contractility, and increased conduction
velocity
C. Pupil constriction and increased gastrointestinal motility
D. Vasodilation and decreased blood pressure
Correct Answer: B
Rationale: Beta-1 adrenergic receptors are primarily located in the heart. Stimulation of
beta-1 receptors by agonists (such as dobutamine) produces positive chronotropic
(increased heart rate), positive inotropic (increased contractility), and positive
dromotropic (increased conduction velocity) effects. Bronchodilation is a beta-2 effect.
Pupil constriction and increased GI motility are parasympathetic (cholinergic) effects.
Vasodilation is primarily a beta-2 or alpha-blocker effect.
Question 6
A client is prescribed a drug that is highly protein-bound (greater than 90% bound to
albumin). The client is also taking warfarin, which is also highly protein-bound. Which
effect should the nurse anticipate?
A. Decreased free warfarin levels and decreased anticoagulant effect
B. Increased free warfarin levels and increased risk of bleeding due to displacement
from protein-binding sites
C. No interaction because both drugs are bound to different proteins
D. Decreased absorption of both drugs in the gastrointestinal tract
Correct Answer: B