NUR 615 Pharmacology Module 1 Exam: Principles of Pharmacokinetics, Pharmacodynamics,
Autonomic Pharmacology, and Drug Development – 2026 Update with Rationales
Questions 1–150 (Complex/Difficult Set)
1. A 72-year-old patient with heart failure (HFrEF), CKD stage 4 (eGFR 25 mL/min), and
hypoalbuminemia (albumin 2.1 g/dL) is started on digoxin 125 mcg daily. After 5 days, she reports
nausea, yellow vision, and heart rate 42 bpm. Digoxin level is 2.8 ng/mL. Which factor MOST
contributed to toxicity?
A) Age-related decrease in renal function
B) Hypoalbuminemia increasing free digoxin fraction
C) CKD reducing digoxin clearance
D) All of the above
Correct Answer: D
Explanation: Digoxin toxicity results from multiple factors: reduced renal clearance (CKD), increased
free drug (hypoalbuminemia), and age-related sensitivity. Each independently increases toxicity risk.
2. A patient is taking warfarin 5 mg daily (INR 2.5). He is started on amiodarone for atrial
fibrillation. One week later, INR is 5.8. Amiodarone inhibits which CYP enzyme responsible for
warfarin metabolism?
A) CYP1A2
B) CYP2C9
C) CYP2D6
D) CYP3A4
Correct Answer: B
Explanation: Warfarin is a racemic mixture; S-warfarin (more potent) is metabolized by CYP2C9.
Amiodarone inhibits CYP2C9 and CYP1A2, significantly increasing INR.
3. A patient with a CYP2C19*2/*2 genotype (poor metabolizer) is prescribed clopidogrel after drug-
eluting stent placement. What is the expected clinical outcome?
A) Enhanced antiplatelet effect
B) Reduced active metabolite formation and increased risk of stent thrombosis
C) No change in platelet inhibition
D) Increased bleeding risk
Correct Answer: B
Explanation: CYP2C19 poor metabolizers cannot convert clopidogrel to its active metabolite, resulting
in high on-treatment platelet reactivity and increased thrombotic risk.
4. A patient on phenytoin has a serum level of 8 mcg/mL (therapeutic 10-20). Albumin is 2.0 g/dL
(normal 4.0). Calculate the corrected phenytoin level. (Correction formula: corrected = measured /
[(0.2 × albumin) + 0.1])
A) 8 mcg/mL
,B) 12 mcg/mL
C) 16 mcg/mL
D) 20 mcg/mL
Correct Answer: C
Explanation: Corrected = 8 / [(0.2×2.0) + 0.1] = 8 / (0.4+0.1) = 8/0.5 = 16 mcg/mL. The measured level
underestimates free drug due to hypoalbuminemia.
5. A patient on warfarin (INR 2.8) is started on rifampin for tuberculosis. After 2 weeks, INR is 1.2.
Rifampin is a strong inducer of which enzymes?
A) CYP2C9 and CYP3A4
B) CYP2D6 only
C) CYP1A2 only
D) CYP2C19 only
Correct Answer: A
Explanation: Rifampin induces multiple CYP enzymes including CYP2C9 (warfarin metabolism) and
CYP3A4, dramatically reducing INR.
6. A patient with myasthenia gravis is taking pyridostigmine. She develops a urinary tract infection
and is prescribed nitrofurantoin. Which statement is correct?
A) No interaction expected
B) Nitrofurantoin may worsen myasthenia (rare but reported)
C) Pyridostigmine dose should be doubled
D) Nitrofurantoin is contraindicated in all myasthenia patients
Correct Answer: B
Explanation: Nitrofurantoin has been reported to exacerbate myasthenia gravis (probably due to
neuromuscular transmission effects). Avoid if possible.
7. A patient on lithium for bipolar disorder develops severe diarrhea and dehydration. Lithium level
is 2.4 mEq/L (therapeutic 0.6-1.2). Which statement best explains this?
A) Dehydration increases renal lithium reabsorption
B) Diarrhea causes direct lithium absorption
C) Lithium metabolism increases in dehydration
D) Lithium protein binding increases
Correct Answer: A
Explanation: Dehydration reduces sodium and water delivery to distal nephron, increasing proximal
tubular lithium reabsorption, leading to toxicity.
8. A patient with G6PD deficiency develops acute hemolytic anemia after being prescribed an
antibiotic. Which drug is the MOST likely cause?
A) Penicillin
B) Doxycycline
C) Trimethoprim-sulfamethoxazole
D) Azithromycin
,Correct Answer: C
Explanation: Sulfonamides (in TMP-SMX) are strong oxidants that cause hemolysis in G6PD deficiency.
9. A patient is taking verapamil for hypertension. He develops atrial fibrillation and is started on
digoxin. After 3 days, he reports nausea and blurred vision. Digoxin level is 2.5 ng/mL. Verapamil
increases digoxin level by:
A) Increasing renal excretion
B) Inhibiting P-glycoprotein (P-gp) in gut and kidney
C) Increasing protein binding
D) Decreasing volume of distribution
Correct Answer: B
Explanation: Verapamil inhibits P-gp, reducing digoxin efflux from enterocytes and renal tubular
secretion, increasing digoxin levels by 50-75%.
10. A patient on theophylline for COPD (level 12 mcg/mL) is started on ciprofloxacin for pneumonia.
What is the expected change in theophylline level?
A) Decrease by 50%
B) Increase by 50-100% (CYP1A2 inhibition)
C) No change
D) Increase by 10%
Correct Answer: B
Explanation: Ciprofloxacin is a strong CYP1A2 inhibitor; theophylline levels can double within days,
risking seizures.
11. A 45-year-old woman with no known liver disease takes acetaminophen 10 grams over 24 hours
for severe headache. She presents 48 hours later with nausea and RUQ pain. AST is 3000 U/L. Which
statement about N-acetylcysteine (NAC) is correct?
A) NAC is only effective within 8 hours of ingestion
B) NAC is effective even at 48 hours if hepatotoxicity is present
C) NAC is not indicated after 24 hours
D) NAC causes hepatotoxicity
Correct Answer: B
Explanation: NAC is effective beyond 8 hours, especially if given before peak liver injury (48-72 hours).
Late NAC improves survival.
12. A patient with pseudocholinesterase deficiency receives succinylcholine for endotracheal
intubation. What is the expected outcome?
A) Normal duration of paralysis (5-10 minutes)
B) Prolonged paralysis (up to 6-8 hours)
C) No effect
D) Malignant hyperthermia
Correct Answer: B
Explanation: Pseudocholinesterase deficiency prevents succinylcholine hydrolysis, causing prolonged
neuromuscular blockade requiring mechanical ventilation.
, 13. A patient on a beta-blocker (metoprolol) and an ACE inhibitor (lisinopril) for heart failure
develops severe bradycardia (HR 38) and hypotension (BP 80/50). Which medication should be
given FIRST?
A) Atropine
B) Glucagon
C) Dopamine
D) IV fluids
Correct Answer: B
Explanation: Glucagon bypasses beta-adrenergic receptors, increasing cAMP and heart rate; effective
in beta-blocker overdose. Atropine may be ineffective.
14. A patient with a history of anaphylaxis to penicillin requires antibiotic prophylaxis for dental
surgery. Which cephalosporin has the LOWEST cross-reactivity?
A) Cephalexin
B) Cefazolin
C) Cefuroxime
D) Cefpodoxime
Correct Answer: B
Explanation: First-generation cephalosporins (cefazolin, cephalexin) have ~1-2% cross-reactivity; later
generations have lower risk but still caution required.
15. A patient on methotrexate for rheumatoid arthritis (15 mg weekly) is prescribed trimethoprim-
sulfamethoxazole for a UTI. Which serious adverse effect is MOST likely?
A) Hepatotoxicity
B) Severe pancytopenia
C) Nephrotoxicity
D) Pulmonary fibrosis
Correct Answer: B
Explanation: TMP inhibits dihydrofolate reductase, additive with methotrexate; can cause severe bone
marrow suppression, mucositis, and death.
16. A patient with a known HLA-B*5701 allele is prescribed which drug? This allele predicts
hypersensitivity to:
A) Carbamazepine
B) Abacavir
C) Allopurinol
D) Phenytoin
Correct Answer: B
Explanation: HLA-B*5701 screening is required before abacavir (HIV drug); positive predicts potentially
fatal hypersensitivity.
17. A patient on clozapine develops fever, tachycardia, and an absolute neutrophil count of
300/mm³. Management includes:
A) Continue clozapine, add filgrastim
Autonomic Pharmacology, and Drug Development – 2026 Update with Rationales
Questions 1–150 (Complex/Difficult Set)
1. A 72-year-old patient with heart failure (HFrEF), CKD stage 4 (eGFR 25 mL/min), and
hypoalbuminemia (albumin 2.1 g/dL) is started on digoxin 125 mcg daily. After 5 days, she reports
nausea, yellow vision, and heart rate 42 bpm. Digoxin level is 2.8 ng/mL. Which factor MOST
contributed to toxicity?
A) Age-related decrease in renal function
B) Hypoalbuminemia increasing free digoxin fraction
C) CKD reducing digoxin clearance
D) All of the above
Correct Answer: D
Explanation: Digoxin toxicity results from multiple factors: reduced renal clearance (CKD), increased
free drug (hypoalbuminemia), and age-related sensitivity. Each independently increases toxicity risk.
2. A patient is taking warfarin 5 mg daily (INR 2.5). He is started on amiodarone for atrial
fibrillation. One week later, INR is 5.8. Amiodarone inhibits which CYP enzyme responsible for
warfarin metabolism?
A) CYP1A2
B) CYP2C9
C) CYP2D6
D) CYP3A4
Correct Answer: B
Explanation: Warfarin is a racemic mixture; S-warfarin (more potent) is metabolized by CYP2C9.
Amiodarone inhibits CYP2C9 and CYP1A2, significantly increasing INR.
3. A patient with a CYP2C19*2/*2 genotype (poor metabolizer) is prescribed clopidogrel after drug-
eluting stent placement. What is the expected clinical outcome?
A) Enhanced antiplatelet effect
B) Reduced active metabolite formation and increased risk of stent thrombosis
C) No change in platelet inhibition
D) Increased bleeding risk
Correct Answer: B
Explanation: CYP2C19 poor metabolizers cannot convert clopidogrel to its active metabolite, resulting
in high on-treatment platelet reactivity and increased thrombotic risk.
4. A patient on phenytoin has a serum level of 8 mcg/mL (therapeutic 10-20). Albumin is 2.0 g/dL
(normal 4.0). Calculate the corrected phenytoin level. (Correction formula: corrected = measured /
[(0.2 × albumin) + 0.1])
A) 8 mcg/mL
,B) 12 mcg/mL
C) 16 mcg/mL
D) 20 mcg/mL
Correct Answer: C
Explanation: Corrected = 8 / [(0.2×2.0) + 0.1] = 8 / (0.4+0.1) = 8/0.5 = 16 mcg/mL. The measured level
underestimates free drug due to hypoalbuminemia.
5. A patient on warfarin (INR 2.8) is started on rifampin for tuberculosis. After 2 weeks, INR is 1.2.
Rifampin is a strong inducer of which enzymes?
A) CYP2C9 and CYP3A4
B) CYP2D6 only
C) CYP1A2 only
D) CYP2C19 only
Correct Answer: A
Explanation: Rifampin induces multiple CYP enzymes including CYP2C9 (warfarin metabolism) and
CYP3A4, dramatically reducing INR.
6. A patient with myasthenia gravis is taking pyridostigmine. She develops a urinary tract infection
and is prescribed nitrofurantoin. Which statement is correct?
A) No interaction expected
B) Nitrofurantoin may worsen myasthenia (rare but reported)
C) Pyridostigmine dose should be doubled
D) Nitrofurantoin is contraindicated in all myasthenia patients
Correct Answer: B
Explanation: Nitrofurantoin has been reported to exacerbate myasthenia gravis (probably due to
neuromuscular transmission effects). Avoid if possible.
7. A patient on lithium for bipolar disorder develops severe diarrhea and dehydration. Lithium level
is 2.4 mEq/L (therapeutic 0.6-1.2). Which statement best explains this?
A) Dehydration increases renal lithium reabsorption
B) Diarrhea causes direct lithium absorption
C) Lithium metabolism increases in dehydration
D) Lithium protein binding increases
Correct Answer: A
Explanation: Dehydration reduces sodium and water delivery to distal nephron, increasing proximal
tubular lithium reabsorption, leading to toxicity.
8. A patient with G6PD deficiency develops acute hemolytic anemia after being prescribed an
antibiotic. Which drug is the MOST likely cause?
A) Penicillin
B) Doxycycline
C) Trimethoprim-sulfamethoxazole
D) Azithromycin
,Correct Answer: C
Explanation: Sulfonamides (in TMP-SMX) are strong oxidants that cause hemolysis in G6PD deficiency.
9. A patient is taking verapamil for hypertension. He develops atrial fibrillation and is started on
digoxin. After 3 days, he reports nausea and blurred vision. Digoxin level is 2.5 ng/mL. Verapamil
increases digoxin level by:
A) Increasing renal excretion
B) Inhibiting P-glycoprotein (P-gp) in gut and kidney
C) Increasing protein binding
D) Decreasing volume of distribution
Correct Answer: B
Explanation: Verapamil inhibits P-gp, reducing digoxin efflux from enterocytes and renal tubular
secretion, increasing digoxin levels by 50-75%.
10. A patient on theophylline for COPD (level 12 mcg/mL) is started on ciprofloxacin for pneumonia.
What is the expected change in theophylline level?
A) Decrease by 50%
B) Increase by 50-100% (CYP1A2 inhibition)
C) No change
D) Increase by 10%
Correct Answer: B
Explanation: Ciprofloxacin is a strong CYP1A2 inhibitor; theophylline levels can double within days,
risking seizures.
11. A 45-year-old woman with no known liver disease takes acetaminophen 10 grams over 24 hours
for severe headache. She presents 48 hours later with nausea and RUQ pain. AST is 3000 U/L. Which
statement about N-acetylcysteine (NAC) is correct?
A) NAC is only effective within 8 hours of ingestion
B) NAC is effective even at 48 hours if hepatotoxicity is present
C) NAC is not indicated after 24 hours
D) NAC causes hepatotoxicity
Correct Answer: B
Explanation: NAC is effective beyond 8 hours, especially if given before peak liver injury (48-72 hours).
Late NAC improves survival.
12. A patient with pseudocholinesterase deficiency receives succinylcholine for endotracheal
intubation. What is the expected outcome?
A) Normal duration of paralysis (5-10 minutes)
B) Prolonged paralysis (up to 6-8 hours)
C) No effect
D) Malignant hyperthermia
Correct Answer: B
Explanation: Pseudocholinesterase deficiency prevents succinylcholine hydrolysis, causing prolonged
neuromuscular blockade requiring mechanical ventilation.
, 13. A patient on a beta-blocker (metoprolol) and an ACE inhibitor (lisinopril) for heart failure
develops severe bradycardia (HR 38) and hypotension (BP 80/50). Which medication should be
given FIRST?
A) Atropine
B) Glucagon
C) Dopamine
D) IV fluids
Correct Answer: B
Explanation: Glucagon bypasses beta-adrenergic receptors, increasing cAMP and heart rate; effective
in beta-blocker overdose. Atropine may be ineffective.
14. A patient with a history of anaphylaxis to penicillin requires antibiotic prophylaxis for dental
surgery. Which cephalosporin has the LOWEST cross-reactivity?
A) Cephalexin
B) Cefazolin
C) Cefuroxime
D) Cefpodoxime
Correct Answer: B
Explanation: First-generation cephalosporins (cefazolin, cephalexin) have ~1-2% cross-reactivity; later
generations have lower risk but still caution required.
15. A patient on methotrexate for rheumatoid arthritis (15 mg weekly) is prescribed trimethoprim-
sulfamethoxazole for a UTI. Which serious adverse effect is MOST likely?
A) Hepatotoxicity
B) Severe pancytopenia
C) Nephrotoxicity
D) Pulmonary fibrosis
Correct Answer: B
Explanation: TMP inhibits dihydrofolate reductase, additive with methotrexate; can cause severe bone
marrow suppression, mucositis, and death.
16. A patient with a known HLA-B*5701 allele is prescribed which drug? This allele predicts
hypersensitivity to:
A) Carbamazepine
B) Abacavir
C) Allopurinol
D) Phenytoin
Correct Answer: B
Explanation: HLA-B*5701 screening is required before abacavir (HIV drug); positive predicts potentially
fatal hypersensitivity.
17. A patient on clozapine develops fever, tachycardia, and an absolute neutrophil count of
300/mm³. Management includes:
A) Continue clozapine, add filgrastim
