Wilkes NSG 533 Exam 1 Advanced Pharmacology 2026/2027 –
Complete Exam- Questions with Detailed Rationales | 100%
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SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS (Q1–Q12)
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Question 1
A 68-year-old male with heart failure is prescribed digoxin 0.25 mg daily. His serum
creatinine is 1.4 mg/dL, weight 70 kg, and age 68. Using the Cockcroft-Gault equation,
his creatinine clearance is approximately 52 mL/min. Digoxin has a narrow therapeutic
index with a therapeutic range of 0.5–0.9 ng/mL. Which pharmacokinetic principle most
directly explains why digoxin requires therapeutic drug monitoring?
A. Digoxin undergoes extensive first-pass metabolism, leading to variable bioavailability
B. Digoxin has a large volume of distribution and is primarily renally eliminated with a
long half-life
C. Digoxin is metabolized by CYP3A4, making it susceptible to numerous drug
interactions
D. Digoxin exhibits zero-order kinetics at therapeutic doses
Correct Answer: B
Rationale:
Digoxin has a large volume of distribution (Vd ~500 L) due to extensive tissue binding,
is primarily eliminated unchanged by the kidneys, and has a long half-life (36–48 hours
in patients with normal renal function, longer in renal impairment). The narrow
therapeutic index combined with renal elimination variability necessitates TDM. Digoxin
,does not undergo significant first-pass metabolism (Option A) or CYP3A4 metabolism
(Option C). It exhibits first-order kinetics (Option D), not zero-order.
Question 2
A 45-year-old female with epilepsy is started on phenytoin 300 mg daily. After 2 weeks,
her serum phenytoin level is 8 mcg/mL (therapeutic range 10–20 mcg/mL). The
prescriber increases the dose to 400 mg daily. At 4 weeks, the level is 18 mcg/mL.
Which pharmacokinetic characteristic of phenytoin explains this disproportionate
increase in serum concentration?
A. Phenytoin exhibits capacity-limited (Michaelis-Menten) metabolism at therapeutic
doses
B. Phenytoin undergoes extensive enterohepatic recirculation
C. Phenytoin is a prodrug requiring hepatic activation
D. Phenytoin has high plasma protein binding that becomes saturated at higher doses
Correct Answer: A
Rationale:
Phenytoin exhibits capacity-limited (Michaelis-Menten) metabolism via CYP2C9 and
CYP2C19. At therapeutic concentrations, the metabolizing enzymes become saturated,
causing small dose increases to produce disproportionately large increases in serum
concentration. This nonlinear pharmacokinetics requires careful titration and TDM.
Enterohepatic recirculation (Option B) is not a major factor for phenytoin. Phenytoin is
not a prodrug (Option C). While highly protein-bound (Option D), saturation of protein
binding is not the primary explanation for the nonlinear dose-concentration relationship.
Question 3
A 55-year-old male with atrial fibrillation is prescribed warfarin 5 mg daily. His INR is 2.5
after 1 week. He then starts amiodarone 400 mg daily for rhythm control. Two weeks
later, his INR is 4.8. Which pharmacokinetic mechanism explains this interaction?
,A. Amiodarone inhibits CYP2C9 and CYP3A4, reducing S-warfarin and R-warfarin
metabolism
B. Amiodarone induces CYP1A2, increasing warfarin clearance
C. Amiodarone displaces warfarin from albumin binding sites, increasing free fraction
D. Amiodarone inhibits vitamin K epoxide reductase (VKORC1) directly
Correct Answer: A
Rationale:
Amiodarone is a potent inhibitor of CYP2C9 (primary metabolizer of S-warfarin, the
more potent enantiomer) and CYP3A4 (metabolizer of R-warfarin). Inhibition of both
pathways reduces warfarin clearance, increasing INR and bleeding risk. Amiodarone
does not induce CYP1A2 (Option B) or significantly displace warfarin from albumin
(Option C). It does not directly inhibit VKORC1 (Option D); that is warfarin's mechanism
of action.
Question 4
A 72-year-old female with community-acquired pneumonia is prescribed levofloxacin
750 mg IV daily. She has a creatinine clearance of 25 mL/min. According to
pharmacokinetic principles and FDA labeling, what dose adjustment is required?
A. No adjustment needed; levofloxacin is hepatically metabolized
B. Reduce to 750 mg every 48 hours
C. Reduce to 500 mg every 48 hours
D. Switch to moxifloxacin 400 mg daily due to superior renal safety
Correct Answer: B
Rationale:
Levofloxacin is primarily renally eliminated (≥87% unchanged). For CrCl 20–49 mL/min,
the FDA-approved adjustment for the 750 mg dose is 750 mg every 48 hours. Reducing
to 500 mg (Option C) is the adjustment for the 500 mg regimen, not the 750 mg
regimen. Levofloxacin is not hepatically metabolized (Option A). Moxifloxacin (Option D)
, has less renal clearance but is not indicated for dose adjustment in this context;
levofloxacin remains effective with proper renal dosing.
Question 5
A 34-year-old female presents with a severe bacterial infection. The prescriber orders
gentamicin 5 mg/kg IV daily. Gentamicin exhibits concentration-dependent killing with a
post-antibiotic effect. Which pharmacodynamic parameter best predicts clinical efficacy
for aminoglycosides?
A. Time above MIC (T>MIC)
B. Peak concentration to MIC ratio (Cmax/MIC)
C. Area under the curve to MIC ratio (AUC/MIC)
D. Minimum inhibitory concentration (MIC) alone
Correct Answer: B
Rationale:
For aminoglycosides, the Cmax/MIC ratio is the primary pharmacodynamic predictor of
efficacy, with a target of ≥8–10 for optimal bactericidal activity.
Concentration-dependent killing and prolonged post-antibiotic effect support once-daily
dosing to maximize peak concentrations. T>MIC (Option A) is critical for beta-lactams.
AUC/MIC (Option C) is the primary parameter for fluoroquinolones and vancomycin.
MIC alone (Option D) does not account for drug exposure.
Question 6
A 60-year-old male with hypertension is prescribed metoprolol succinate 50 mg daily.
He has hepatic cirrhosis (Child-Pugh Class B). Metoprolol is extensively metabolized by
CYP2D6. Which pharmacokinetic change is most likely in this patient?
A. Increased hepatic blood flow leading to increased first-pass metabolism
B. Decreased hepatic metabolism leading to increased bioavailability and drug
accumulation
C. Increased plasma protein binding due to decreased albumin synthesis
Complete Exam- Questions with Detailed Rationales | 100%
Verified – Pass Guaranteed – A+ Graded
──────────────────────────────
SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS (Q1–Q12)
──────────────────────────────
Question 1
A 68-year-old male with heart failure is prescribed digoxin 0.25 mg daily. His serum
creatinine is 1.4 mg/dL, weight 70 kg, and age 68. Using the Cockcroft-Gault equation,
his creatinine clearance is approximately 52 mL/min. Digoxin has a narrow therapeutic
index with a therapeutic range of 0.5–0.9 ng/mL. Which pharmacokinetic principle most
directly explains why digoxin requires therapeutic drug monitoring?
A. Digoxin undergoes extensive first-pass metabolism, leading to variable bioavailability
B. Digoxin has a large volume of distribution and is primarily renally eliminated with a
long half-life
C. Digoxin is metabolized by CYP3A4, making it susceptible to numerous drug
interactions
D. Digoxin exhibits zero-order kinetics at therapeutic doses
Correct Answer: B
Rationale:
Digoxin has a large volume of distribution (Vd ~500 L) due to extensive tissue binding,
is primarily eliminated unchanged by the kidneys, and has a long half-life (36–48 hours
in patients with normal renal function, longer in renal impairment). The narrow
therapeutic index combined with renal elimination variability necessitates TDM. Digoxin
,does not undergo significant first-pass metabolism (Option A) or CYP3A4 metabolism
(Option C). It exhibits first-order kinetics (Option D), not zero-order.
Question 2
A 45-year-old female with epilepsy is started on phenytoin 300 mg daily. After 2 weeks,
her serum phenytoin level is 8 mcg/mL (therapeutic range 10–20 mcg/mL). The
prescriber increases the dose to 400 mg daily. At 4 weeks, the level is 18 mcg/mL.
Which pharmacokinetic characteristic of phenytoin explains this disproportionate
increase in serum concentration?
A. Phenytoin exhibits capacity-limited (Michaelis-Menten) metabolism at therapeutic
doses
B. Phenytoin undergoes extensive enterohepatic recirculation
C. Phenytoin is a prodrug requiring hepatic activation
D. Phenytoin has high plasma protein binding that becomes saturated at higher doses
Correct Answer: A
Rationale:
Phenytoin exhibits capacity-limited (Michaelis-Menten) metabolism via CYP2C9 and
CYP2C19. At therapeutic concentrations, the metabolizing enzymes become saturated,
causing small dose increases to produce disproportionately large increases in serum
concentration. This nonlinear pharmacokinetics requires careful titration and TDM.
Enterohepatic recirculation (Option B) is not a major factor for phenytoin. Phenytoin is
not a prodrug (Option C). While highly protein-bound (Option D), saturation of protein
binding is not the primary explanation for the nonlinear dose-concentration relationship.
Question 3
A 55-year-old male with atrial fibrillation is prescribed warfarin 5 mg daily. His INR is 2.5
after 1 week. He then starts amiodarone 400 mg daily for rhythm control. Two weeks
later, his INR is 4.8. Which pharmacokinetic mechanism explains this interaction?
,A. Amiodarone inhibits CYP2C9 and CYP3A4, reducing S-warfarin and R-warfarin
metabolism
B. Amiodarone induces CYP1A2, increasing warfarin clearance
C. Amiodarone displaces warfarin from albumin binding sites, increasing free fraction
D. Amiodarone inhibits vitamin K epoxide reductase (VKORC1) directly
Correct Answer: A
Rationale:
Amiodarone is a potent inhibitor of CYP2C9 (primary metabolizer of S-warfarin, the
more potent enantiomer) and CYP3A4 (metabolizer of R-warfarin). Inhibition of both
pathways reduces warfarin clearance, increasing INR and bleeding risk. Amiodarone
does not induce CYP1A2 (Option B) or significantly displace warfarin from albumin
(Option C). It does not directly inhibit VKORC1 (Option D); that is warfarin's mechanism
of action.
Question 4
A 72-year-old female with community-acquired pneumonia is prescribed levofloxacin
750 mg IV daily. She has a creatinine clearance of 25 mL/min. According to
pharmacokinetic principles and FDA labeling, what dose adjustment is required?
A. No adjustment needed; levofloxacin is hepatically metabolized
B. Reduce to 750 mg every 48 hours
C. Reduce to 500 mg every 48 hours
D. Switch to moxifloxacin 400 mg daily due to superior renal safety
Correct Answer: B
Rationale:
Levofloxacin is primarily renally eliminated (≥87% unchanged). For CrCl 20–49 mL/min,
the FDA-approved adjustment for the 750 mg dose is 750 mg every 48 hours. Reducing
to 500 mg (Option C) is the adjustment for the 500 mg regimen, not the 750 mg
regimen. Levofloxacin is not hepatically metabolized (Option A). Moxifloxacin (Option D)
, has less renal clearance but is not indicated for dose adjustment in this context;
levofloxacin remains effective with proper renal dosing.
Question 5
A 34-year-old female presents with a severe bacterial infection. The prescriber orders
gentamicin 5 mg/kg IV daily. Gentamicin exhibits concentration-dependent killing with a
post-antibiotic effect. Which pharmacodynamic parameter best predicts clinical efficacy
for aminoglycosides?
A. Time above MIC (T>MIC)
B. Peak concentration to MIC ratio (Cmax/MIC)
C. Area under the curve to MIC ratio (AUC/MIC)
D. Minimum inhibitory concentration (MIC) alone
Correct Answer: B
Rationale:
For aminoglycosides, the Cmax/MIC ratio is the primary pharmacodynamic predictor of
efficacy, with a target of ≥8–10 for optimal bactericidal activity.
Concentration-dependent killing and prolonged post-antibiotic effect support once-daily
dosing to maximize peak concentrations. T>MIC (Option A) is critical for beta-lactams.
AUC/MIC (Option C) is the primary parameter for fluoroquinolones and vancomycin.
MIC alone (Option D) does not account for drug exposure.
Question 6
A 60-year-old male with hypertension is prescribed metoprolol succinate 50 mg daily.
He has hepatic cirrhosis (Child-Pugh Class B). Metoprolol is extensively metabolized by
CYP2D6. Which pharmacokinetic change is most likely in this patient?
A. Increased hepatic blood flow leading to increased first-pass metabolism
B. Decreased hepatic metabolism leading to increased bioavailability and drug
accumulation
C. Increased plasma protein binding due to decreased albumin synthesis
