NSG5240 Midterm Review Advanced
Pharmacology Therapeutics Official Practice
Exam Actual Exam 2026/2027 with Detailed
Rationales | Complete Exam-Style Questions |
Pass Guaranteed – A+ Graded
══════════════════════════════════════
SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS Q1 – Q10
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Question 1 of 50
A 78-year-old man with chronic heart failure and hypoalbuminemia (albumin 2.8 g/dL) is
started on intravenous furosemide and warfarin for new-onset atrial fibrillation. On day 5, his
INR is 4.2 despite a standard 5 mg daily dose. He has no dietary changes, bleeding, or signs
of liver failure. The prescriber suspects an altered pharmacokinetic property is exaggerating
warfarin's effect.
A. Decreased hepatic blood flow reducing first-pass metabolism
B. Increased volume of distribution due to peripheral edema
C. Reduced protein binding increasing free drug fraction ✓ CORRECT
D. Enhanced renal clearance of the S-warfarin isomer
Correct Answer: C
Rationale: Hypoalbuminemia reduces warfarin binding sites, increasing the unbound (free)
fraction that is pharmacologically active and leading to excessive anticoagulation at standard
doses. Decreased protein binding is a well-documented cause of exaggerated drug response
in elderly and malnourished patients, not increased renal clearance of the active isomer.
Always verify albumin levels and consider lower initial warfarin doses in patients with low
albumin.
Question 2 of 50
A 45-year-old woman with bipolar disorder has been stable on lithium carbonate 900 mg
twice daily for three years. She develops a severe urinary tract infection and is prescribed
trimethoprim-sulfamethoxazole DS twice daily. Three days later, she presents with confusion,
coarse tremor, and ataxia. Her lithium level is 2.4 mEq/L. The prescriber recognizes that this
drug interaction involves a critical pharmacokinetic mechanism.
,A. Trimethoprim induces CYP1A2, reducing lithium metabolism
B. Trimethoprim decreases lithium renal clearance through competition at the proximal
tubule ✓ CORRECT
C. Sulfamethoxazole displaces lithium from albumin binding sites
D. The antibiotic increases lithium hepatic glucuronidation
Correct Answer: B
Rationale: Trimethoprim competes with lithium for renal tubular secretion via the organic
cation transporter in the proximal tubule, significantly reducing lithium clearance and
precipitating toxicity even at stable doses. Lithium is not hepatically metabolized and is not
protein bound, so displacement or enzyme induction explanations are pharmacologically
implausible. Always hold or reduce lithium and monitor levels when prescribing drugs that
compete for renal elimination.
Question 3 of 50
A 62-year-old man with recurrent Clostridioides difficile infection is prescribed rifaximin 550
mg three times daily to suppress further episodes. His other medications include
atorvastatin 40 mg daily, amlodipine 5 mg daily, and a transdermal estradiol patch 0.05
mg/day for osteoporosis prevention. After two weeks, he reports breakthrough hot flashes
and his LDL cholesterol has risen from 98 to 142 mg/dL. The nurse practitioner identifies the
most likely mechanism.
A. Rifaximin inhibits intestinal CYP3A4, reducing statin absorption
B. Rifaximin induces hepatic CYP3A4 and P-glycoprotein, accelerating metabolism of
atorvastatin and estradiol
C. Rifaximin chelates calcium in the gut, blocking estradiol absorption
D. Rifaximin displaces atorvastatin from albumin, increasing its renal clearance ✓ CORRECT
Correct Answer: B
Rationale: Although rifaximin has minimal systemic absorption, it induces hepatic CYP3A4
and intestinal P-glycoprotein at higher doses, increasing the metabolism and reducing the
bioavailability of CYP3A4 substrates like atorvastatin and transdermal estradiol. Rifaximin
does not chelate minerals or significantly alter albumin binding, and the transdermal route
bypasses first-pass metabolism but still relies on hepatic clearance. Review all CYP3A4
substrates when starting any rifamycin derivative.
Question 4 of 50
A 58-year-old woman with metastatic breast cancer receiving high-dose morphine via
patient-controlled analgesia reports inadequate pain control despite escalating doses. Her
pharmacist suggests switching to an equianalgesic dose of hydromorphone. The primary
pharmacodynamic rationale for improved efficacy with this rotation is:
, A. Hydromorphone has a higher intrinsic activity at the mu-opioid receptor and lacks active
metabolites that accumulate in renal impairment ✓ CORRECT
B. Hydromorphone is a partial agonist with a ceiling effect that prevents overdose
C. Hydromorphone primarily acts on kappa receptors, avoiding mu-receptor tolerance
D. Morphine and hydromorphone share identical receptor profiles, so the benefit is purely
psychological
Correct Answer: A
Rationale: Hydromorphone is a pure mu-opioid agonist with greater receptor affinity and no
accumulation of neurotoxic metabolites (M3G, M6G) that occur with morphine, especially in
renal dysfunction or with prolonged high-dose therapy. Hydromorphone is not a partial
agonist and does not primarily target kappa receptors, and equianalgesic rotation relies on
real pharmacodynamic differences, not placebo effects. Consider hydromorphone or fentanyl
when morphine metabolite accumulation causes neurotoxicity or hyperalgesia.
Question 5 of 50
A 34-year-old woman post-gastric bypass surgery is prescribed propranolol 20 mg twice daily
for migraine prophylaxis. After four weeks, she reports no reduction in migraine frequency.
Her blood pressure is unchanged, and she has no adverse effects. The prescriber recognizes
that altered pharmacokinetics following bariatric surgery explain this therapeutic failure.
A. Increased gastric pH reducing propranolol ionization and absorption
B. Reduced first-pass hepatic metabolism due to altered portal circulation and gut hormone
changes ✓ CORRECT
C. Accelerated gastric emptying increasing propranolol clearance
D. Decreased bile acid secretion preventing propranolol solubilization
Correct Answer: B
Rationale: Roux-en-Y gastric bypass alters splanchnic blood flow and gut hormone signaling,
which can reduce hepatic first-pass metabolism and paradoxically lower peak plasma
concentrations of high-extraction drugs like propranolol that depend on extensive
presystemic metabolism. Propranolol is a lipophilic, non-ionized drug that does not depend
on gastric pH for absorption, and accelerated gastric emptying does not increase drug
clearance. Reassess dosing or consider agents less dependent on first-pass metabolism
after bariatric surgery.
Question 6 of 50
A 50-year-old man with major depressive disorder is started on fluoxetine 20 mg daily. He is a
CYP2D6 poor metabolizer based on pharmacogenomic testing. Two weeks later, he develops
severe insomnia, agitation, and restlessness. His fluoxetine level is three times the expected
therapeutic range. The prescriber must select the most appropriate next step based on his
pharmacogenomic profile.
Pharmacology Therapeutics Official Practice
Exam Actual Exam 2026/2027 with Detailed
Rationales | Complete Exam-Style Questions |
Pass Guaranteed – A+ Graded
══════════════════════════════════════
SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A 78-year-old man with chronic heart failure and hypoalbuminemia (albumin 2.8 g/dL) is
started on intravenous furosemide and warfarin for new-onset atrial fibrillation. On day 5, his
INR is 4.2 despite a standard 5 mg daily dose. He has no dietary changes, bleeding, or signs
of liver failure. The prescriber suspects an altered pharmacokinetic property is exaggerating
warfarin's effect.
A. Decreased hepatic blood flow reducing first-pass metabolism
B. Increased volume of distribution due to peripheral edema
C. Reduced protein binding increasing free drug fraction ✓ CORRECT
D. Enhanced renal clearance of the S-warfarin isomer
Correct Answer: C
Rationale: Hypoalbuminemia reduces warfarin binding sites, increasing the unbound (free)
fraction that is pharmacologically active and leading to excessive anticoagulation at standard
doses. Decreased protein binding is a well-documented cause of exaggerated drug response
in elderly and malnourished patients, not increased renal clearance of the active isomer.
Always verify albumin levels and consider lower initial warfarin doses in patients with low
albumin.
Question 2 of 50
A 45-year-old woman with bipolar disorder has been stable on lithium carbonate 900 mg
twice daily for three years. She develops a severe urinary tract infection and is prescribed
trimethoprim-sulfamethoxazole DS twice daily. Three days later, she presents with confusion,
coarse tremor, and ataxia. Her lithium level is 2.4 mEq/L. The prescriber recognizes that this
drug interaction involves a critical pharmacokinetic mechanism.
,A. Trimethoprim induces CYP1A2, reducing lithium metabolism
B. Trimethoprim decreases lithium renal clearance through competition at the proximal
tubule ✓ CORRECT
C. Sulfamethoxazole displaces lithium from albumin binding sites
D. The antibiotic increases lithium hepatic glucuronidation
Correct Answer: B
Rationale: Trimethoprim competes with lithium for renal tubular secretion via the organic
cation transporter in the proximal tubule, significantly reducing lithium clearance and
precipitating toxicity even at stable doses. Lithium is not hepatically metabolized and is not
protein bound, so displacement or enzyme induction explanations are pharmacologically
implausible. Always hold or reduce lithium and monitor levels when prescribing drugs that
compete for renal elimination.
Question 3 of 50
A 62-year-old man with recurrent Clostridioides difficile infection is prescribed rifaximin 550
mg three times daily to suppress further episodes. His other medications include
atorvastatin 40 mg daily, amlodipine 5 mg daily, and a transdermal estradiol patch 0.05
mg/day for osteoporosis prevention. After two weeks, he reports breakthrough hot flashes
and his LDL cholesterol has risen from 98 to 142 mg/dL. The nurse practitioner identifies the
most likely mechanism.
A. Rifaximin inhibits intestinal CYP3A4, reducing statin absorption
B. Rifaximin induces hepatic CYP3A4 and P-glycoprotein, accelerating metabolism of
atorvastatin and estradiol
C. Rifaximin chelates calcium in the gut, blocking estradiol absorption
D. Rifaximin displaces atorvastatin from albumin, increasing its renal clearance ✓ CORRECT
Correct Answer: B
Rationale: Although rifaximin has minimal systemic absorption, it induces hepatic CYP3A4
and intestinal P-glycoprotein at higher doses, increasing the metabolism and reducing the
bioavailability of CYP3A4 substrates like atorvastatin and transdermal estradiol. Rifaximin
does not chelate minerals or significantly alter albumin binding, and the transdermal route
bypasses first-pass metabolism but still relies on hepatic clearance. Review all CYP3A4
substrates when starting any rifamycin derivative.
Question 4 of 50
A 58-year-old woman with metastatic breast cancer receiving high-dose morphine via
patient-controlled analgesia reports inadequate pain control despite escalating doses. Her
pharmacist suggests switching to an equianalgesic dose of hydromorphone. The primary
pharmacodynamic rationale for improved efficacy with this rotation is:
, A. Hydromorphone has a higher intrinsic activity at the mu-opioid receptor and lacks active
metabolites that accumulate in renal impairment ✓ CORRECT
B. Hydromorphone is a partial agonist with a ceiling effect that prevents overdose
C. Hydromorphone primarily acts on kappa receptors, avoiding mu-receptor tolerance
D. Morphine and hydromorphone share identical receptor profiles, so the benefit is purely
psychological
Correct Answer: A
Rationale: Hydromorphone is a pure mu-opioid agonist with greater receptor affinity and no
accumulation of neurotoxic metabolites (M3G, M6G) that occur with morphine, especially in
renal dysfunction or with prolonged high-dose therapy. Hydromorphone is not a partial
agonist and does not primarily target kappa receptors, and equianalgesic rotation relies on
real pharmacodynamic differences, not placebo effects. Consider hydromorphone or fentanyl
when morphine metabolite accumulation causes neurotoxicity or hyperalgesia.
Question 5 of 50
A 34-year-old woman post-gastric bypass surgery is prescribed propranolol 20 mg twice daily
for migraine prophylaxis. After four weeks, she reports no reduction in migraine frequency.
Her blood pressure is unchanged, and she has no adverse effects. The prescriber recognizes
that altered pharmacokinetics following bariatric surgery explain this therapeutic failure.
A. Increased gastric pH reducing propranolol ionization and absorption
B. Reduced first-pass hepatic metabolism due to altered portal circulation and gut hormone
changes ✓ CORRECT
C. Accelerated gastric emptying increasing propranolol clearance
D. Decreased bile acid secretion preventing propranolol solubilization
Correct Answer: B
Rationale: Roux-en-Y gastric bypass alters splanchnic blood flow and gut hormone signaling,
which can reduce hepatic first-pass metabolism and paradoxically lower peak plasma
concentrations of high-extraction drugs like propranolol that depend on extensive
presystemic metabolism. Propranolol is a lipophilic, non-ionized drug that does not depend
on gastric pH for absorption, and accelerated gastric emptying does not increase drug
clearance. Reassess dosing or consider agents less dependent on first-pass metabolism
after bariatric surgery.
Question 6 of 50
A 50-year-old man with major depressive disorder is started on fluoxetine 20 mg daily. He is a
CYP2D6 poor metabolizer based on pharmacogenomic testing. Two weeks later, he develops
severe insomnia, agitation, and restlessness. His fluoxetine level is three times the expected
therapeutic range. The prescriber must select the most appropriate next step based on his
pharmacogenomic profile.
