Advanced Practice Nurses ACTUAL
EXAM | 3rd Edition 2023 | Rosenthal |
Comprehensive Study Guide | Practice
Question Bank | Verified Q&A | Pass
Guaranteed - A+ Graded
UNIT 1: PRINCIPLES OF PHARMACOTHERAPY
Q1: A 70-year-old patient with chronic kidney disease (eGFR 35 mL/min) is
prescribed a new medication that is renally eliminated. What adjustment is
most appropriate?
A. Standard loading dose with decreased maintenance dose based on renal function
[CORRECT]
B. Standard loading and maintenance doses with increased monitoring
C. Increased loading dose with standard maintenance dose
D. Decreased loading dose with standard maintenance dose
Correct Answer: A
Rationale: In renal impairment, the loading dose (based on volume of distribution) typically
remains unchanged, while the maintenance dose must be reduced to account for
decreased drug clearance and prevent toxicity. Standard doses (B) risk accumulation.
Increased loading dose (C) is incorrect. Decreased loading dose (D) may lead to subtherapeutic
levels.
Lehne’s Note: Renal impairment = STANDARD LOADING DOSE + REDUCED
MAINTENANCE DOSE—prevent drug accumulation!
,Q2: Which pharmacokinetic change associated with aging requires careful
consideration when prescribing for geriatric patients?
A. Increased first-pass metabolism in the liver
B. Decreased gastric pH affecting drug absorption
C. Reduced glomerular filtration rate affecting drug excretion [CORRECT]
D. Increased plasma protein binding
Correct Answer: C
Rationale: Aging reduces glomerular filtration rate (GFR), leading to decreased renal
drug clearance and risk of drug accumulation. First-pass metabolism (A) often decreases
with age. Gastric pH (B) increases (hypochlorhydria), potentially reducing absorption of weakly
acidic drugs. Plasma protein binding (D) decreases due to lower albumin levels.
Lehne’s Note: Geriatrics = REDUCED GFR—adjust doses for renally cleared drugs!
Q3: A patient with a CYP2D6 poor metabolizer genotype is prescribed codeine
for pain. What is the most likely outcome?
A. Increased risk of opioid toxicity due to reduced metabolism to morphine [CORRECT]
B. Enhanced analgesic effect due to rapid conversion to morphine
C. No change in drug effect compared to extensive metabolizers
D. Increased risk of serotonin syndrome
Correct Answer: A
Rationale: CYP2D6 poor metabolizers cannot efficiently convert codeine to its active
metabolite, morphine , resulting in reduced analgesic effect and increased risk of toxicity if
dose is not adjusted. Enhanced effect (B) occurs in ultra-rapid metabolizers. No change (C) is
incorrect. Serotonin syndrome (D) is unrelated to CYP2D6 metabolism of codeine.
Lehne’s Note: CYP2D6 poor metabolizers = REDUCED CODEINE EFFICACY +
TOXICITY RISK—avoid codeine or use alternative analgesics!
Q4: Which of the following best describes the therapeutic index of a drug?
A. The ratio of the drug’s half-life to its duration of action
B. The ratio of the toxic dose to the effective dose (TD50/ED50) [CORRECT]
C. The time required for the drug to reach steady state
D. The drug’s affinity for its target receptor
Correct Answer: B
Rationale: The therapeutic index (TI) is defined as the ratio of the toxic dose (TD50) to the
effective dose (ED50), indicating the safety margin of a drug. A narrow TI (e.g., digoxin,
,warfarin) requires close monitoring. Half-life (A), steady state (C), and receptor affinity (D) are
unrelated to TI.
Lehne’s Note: Therapeutic index = TD50/ED50—narrow TI = HIGH RISK (e.g., digoxin,
lithium, warfarin)!
Q5: A patient is prescribed a drug with a half-life of 6 hours. How long will it
take to reach steady state?
A. 6 hours
B. 12 hours
C. 30 hours (approximately 5 half-lives) [CORRECT]
D. 72 hours
Correct Answer: C
Rationale: Steady state is reached after 4–5 half-lives. For a drug with a 6-hour half-life,
steady state is achieved in ~30 hours (5 × 6). Shorter times (A/B) are insufficient. 72 hours (D)
is excessive.
Lehne’s Note: Steady state = 4–5 half-lives—critical for dosing adjustments!
Q6: Which of the following is the primary mechanism by which grapefruit juice
alters drug metabolism?
A. Induction of CYP3A4
B. Inhibition of CYP3A4 in the intestinal wall [CORRECT]
C. Increased renal excretion of drugs
D. Enhanced first-pass metabolism
Correct Answer: B
Rationale: Grapefruit juice irreversibly inhibits CYP3A4 in the intestinal wall, reducing
first-pass metabolism and increasing bioavailability of drugs like statins, calcium channel
blockers, and immunosuppressants. Induction (A) would decrease drug levels. Renal
excretion (C) and enhanced first-pass metabolism (D) are incorrect.
Lehne’s Note: Grapefruit juice = CYP3A4 INHIBITION—↑ drug levels (e.g., simvastatin,
amlodipine, cyclosporine)!
Q7: A patient with heart failure is prescribed furosemide and digoxin. Which of
the following is a potential drug-drug interaction?
, A. Furosemide increases digoxin absorption
B. Furosemide-induced hypokalemia increases the risk of digoxin toxicity [CORRECT]
C. Digoxin reduces the diuretic effect of furosemide
D. Both drugs compete for renal excretion, leading to reduced clearance
Correct Answer: B
Rationale: Furosemide can cause hypokalemia, which enhances digoxin’s binding to
Na+/K+ ATPase , increasing the risk of digoxin toxicity (e.g., arrhythmias). Furosemide does
not affect digoxin absorption (A). Digoxin does not reduce furosemide’s diuretic effect (C). Renal
competition (D) is not the primary interaction.
Lehne’s Note: Furosemide + digoxin = MONITOR K+—hypokalemia ↑ digoxin toxicity
risk!
Q8: Which of the following is a Phase I metabolic reaction?
A. Glucuronidation
B. Oxidation by CYP450 enzymes [CORRECT]
C. Acetylation
D. Sulfation
Correct Answer: B
Rationale: Phase I reactions (e.g., oxidation, reduction, hydrolysis) modify drugs to make
them more polar, often via CYP450 enzymes. Phase II reactions (A/C/D) involve conjugation
(e.g., glucuronidation, acetylation, sulfation).
Lehne’s Note: Phase I = MODIFICATION (CYP450); Phase II = CONJUGATION!
Q9: A patient with liver cirrhosis is prescribed lorazepam. Why is this drug
preferred over diazepam in this population?
A. Lorazepam has a shorter half-life and is not metabolized by the liver [CORRECT]
B. Diazepam is more likely to cause respiratory depression
C. Lorazepam has a higher therapeutic index than diazepam
D. Diazepam is contraindicated in cirrhosis due to renal toxicity
Correct Answer: A
Rationale: Lorazepam undergoes glucuronidation (Phase II), which is preserved in
cirrhosis, while diazepam requires CYP450 oxidation (Phase I), which is impaired in liver
disease . Respiratory depression (B) is a class effect. Therapeutic index (C) is similar.
Diazepam is not contraindicated due to renal toxicity (D).
Lehne’s Note: Cirrhosis = AVOID PHASE I METABOLISM —lorazepam > diazepam!