NR 565 – Advanced Pharmacology Final
Exam | 2025/2026 Verified Expert Drug
Questions and Answers
Section 1: Pharmacokinetics (Questions 1–13)
Question 1: A 68-year-old patient with renal impairment (CrCl 30 mL/min) is prescribed gabapentin for
neuropathic pain. What PK adjustment is required due to reduced clearance?
A. Increase dose to 600 mg TID.
B. Reduce dose to 100-300 mg daily.
C. No change; hepatic metabolism dominant.
D. Switch to IV formulation.
Rationale: Gabapentin undergoes renal excretion (90% unchanged), with half-life prolonged from 5-7h to
52h in CrCl <30 mL/min (PK: elimination). Dose adjustment per Cockcroft-Gault prevents
accumulation/toxicity (sedation). FDA labeling (2025) and Beers Criteria recommend renal titration for
elderly.
Question 2: For vancomycin IV in obesity (BMI 40), what PK parameter guides dosing:
A. Ideal body weight for loading.
B. Total body weight for volume of distribution.
C. Lean mass only.
D. Height-based.
Rationale: Vancomycin's Vd increases with adipose tissue (~0.7 L/kg TBW), but clearance ties to renal
function (CrCl). AUC/MIC 400-600 target; obese dosing uses TBW for initial (IDSA, 2025) to achieve
trough 15-20 mcg/mL, minimizing nephrotoxicity.
Question 3: A patient on enteral nutrition starts levothyroxine. What PK effect delays absorption?
A. Increased bioavailability.
B. Reduced gastric emptying and binding to soy fiber.
C. Enhanced hepatic first-pass.
D. No impact.
Rationale: Enteral formulas (soy-based) bind T4, reducing absorption by 20-30% (PK: oral
bioavailability 40-80%). Monitor TSH; separate by 4h or crush/suspend in water (Endo Society, 2025).
Question 4: Digoxin's narrow therapeutic index requires PK monitoring of:
A. Serum albumin.
,B. Renal function (CrCl) and electrolytes.
C. Liver enzymes.
D. CBC.
Rationale: 60-80% renal clearance; hypokalemia (K+ <3.5 mEq/L) potentiates toxicity (V_d 5-7 L/kg,
half-life 36-48h). Levels 0.5-2 ng/mL; AHA HF guidelines (2025) advise q6 months in elderly.
Question 5: Warfarin's PK is affected by CYP2C9 polymorphisms, leading to:
A. Faster metabolism.
B. Reduced clearance and higher INR.
C. Increased Vd.
D. No effect.
Rationale: Poor metabolizers (e.g., *2/*3 alleles) halve clearance, prolonging half-life >40h (PK: hepatic
metabolism). Genotyping guides initial 2-5 mg dosing; ACC (2025) recommends pharmacogenomics.
Question 6: In hepatic cirrhosis, lidocaine's PK change requires:
A. Dose increase.
B. Dose reduction due to prolonged half-life.
C. Frequent loading.
D. IV only.
Rationale: Reduced phase I metabolism (CYP3A4) extends half-life from 1.5h to 5h (V_d unchanged).
Child-Pugh scoring adjusts; ASRA pain guidelines (2025) limit to 1-2 mg/kg.
Question 7: Grapefruit juice inhibits CYP3A4, affecting PK of:
A. Warfarin (increased effect).
B. Simvastatin (increased AUC).
C. Aspirin.
D. Metformin.
Rationale: Inhibition raises simvastatin bioavailability (AUC x10), risking myopathy (PK: first-pass).
Advise avoidance; FDA drug-food interactions (2025).
Question 8: For pediatric amoxicillin dosing, what PK principle uses mg/kg?
A. Fixed adult dose.
B. Allometric scaling for immature clearance.
C. Hepatic adjustment.
D. Renal only.
Rationale: Immature renal/hepatic function requires 40-90 mg/kg/day divided; half-life 1-2h in neonates
vs. 1h adults. AAP antibiotic stewardship (2025).
, Question 9: Theophylline clearance decreases in heart failure due to:
A. Increased Vd.
B. Reduced hepatic blood flow.
C. Renal hyperfunction.
D. Protein binding.
Rationale: Low cardiac output halves clearance (half-life 9h → 25h), levels 5-15 mcg/mL. GINA asthma
(2025) favors alternatives due to PK variability.
Question 10: Bioavailability of oral morphine is:
A. 100%.
B. 20-30% due to first-pass.
C. 50%.
D. 80%.
Rationale: Extensive hepatic glucuronidation (UGT2B7) reduces F=24%; equipotent IV 3x oral. ASRA
opioid guidelines (2025) for PCA titration.
Question 11: In pregnancy, physiological PK changes include increased Vd for:
A. Lipophilic drugs (decreased).
B. Water-soluble drugs like aminoglycosides.
C. Protein-bound only.
D. Hepatic enzymes.
Rationale: Plasma volume +50% expands Vd (e.g., gentamicin 0.25 → 0.4 L/kg), requiring dose
increase. ACOG pharmacotherapy (2025).
Question 12: Steady-state for once-daily drug with 24h half-life is reached in:
A. 1 day.
B. 4-5 days (3.3 half-lives).
C. 24 hours.
D. 7 days.
Rationale: Css = (F × Dose / τ) / (1 - e^{-kτ}); 90% at 3-4 half-lives. Loading doses accelerate for
anticoagulants (ACC, 2025).
Question 13: Protein binding displacement interaction for warfarin by aspirin affects:
A. Vd.
B. Free fraction and anticoagulant effect.
C. Clearance.
D. Absorption.
Exam | 2025/2026 Verified Expert Drug
Questions and Answers
Section 1: Pharmacokinetics (Questions 1–13)
Question 1: A 68-year-old patient with renal impairment (CrCl 30 mL/min) is prescribed gabapentin for
neuropathic pain. What PK adjustment is required due to reduced clearance?
A. Increase dose to 600 mg TID.
B. Reduce dose to 100-300 mg daily.
C. No change; hepatic metabolism dominant.
D. Switch to IV formulation.
Rationale: Gabapentin undergoes renal excretion (90% unchanged), with half-life prolonged from 5-7h to
52h in CrCl <30 mL/min (PK: elimination). Dose adjustment per Cockcroft-Gault prevents
accumulation/toxicity (sedation). FDA labeling (2025) and Beers Criteria recommend renal titration for
elderly.
Question 2: For vancomycin IV in obesity (BMI 40), what PK parameter guides dosing:
A. Ideal body weight for loading.
B. Total body weight for volume of distribution.
C. Lean mass only.
D. Height-based.
Rationale: Vancomycin's Vd increases with adipose tissue (~0.7 L/kg TBW), but clearance ties to renal
function (CrCl). AUC/MIC 400-600 target; obese dosing uses TBW for initial (IDSA, 2025) to achieve
trough 15-20 mcg/mL, minimizing nephrotoxicity.
Question 3: A patient on enteral nutrition starts levothyroxine. What PK effect delays absorption?
A. Increased bioavailability.
B. Reduced gastric emptying and binding to soy fiber.
C. Enhanced hepatic first-pass.
D. No impact.
Rationale: Enteral formulas (soy-based) bind T4, reducing absorption by 20-30% (PK: oral
bioavailability 40-80%). Monitor TSH; separate by 4h or crush/suspend in water (Endo Society, 2025).
Question 4: Digoxin's narrow therapeutic index requires PK monitoring of:
A. Serum albumin.
,B. Renal function (CrCl) and electrolytes.
C. Liver enzymes.
D. CBC.
Rationale: 60-80% renal clearance; hypokalemia (K+ <3.5 mEq/L) potentiates toxicity (V_d 5-7 L/kg,
half-life 36-48h). Levels 0.5-2 ng/mL; AHA HF guidelines (2025) advise q6 months in elderly.
Question 5: Warfarin's PK is affected by CYP2C9 polymorphisms, leading to:
A. Faster metabolism.
B. Reduced clearance and higher INR.
C. Increased Vd.
D. No effect.
Rationale: Poor metabolizers (e.g., *2/*3 alleles) halve clearance, prolonging half-life >40h (PK: hepatic
metabolism). Genotyping guides initial 2-5 mg dosing; ACC (2025) recommends pharmacogenomics.
Question 6: In hepatic cirrhosis, lidocaine's PK change requires:
A. Dose increase.
B. Dose reduction due to prolonged half-life.
C. Frequent loading.
D. IV only.
Rationale: Reduced phase I metabolism (CYP3A4) extends half-life from 1.5h to 5h (V_d unchanged).
Child-Pugh scoring adjusts; ASRA pain guidelines (2025) limit to 1-2 mg/kg.
Question 7: Grapefruit juice inhibits CYP3A4, affecting PK of:
A. Warfarin (increased effect).
B. Simvastatin (increased AUC).
C. Aspirin.
D. Metformin.
Rationale: Inhibition raises simvastatin bioavailability (AUC x10), risking myopathy (PK: first-pass).
Advise avoidance; FDA drug-food interactions (2025).
Question 8: For pediatric amoxicillin dosing, what PK principle uses mg/kg?
A. Fixed adult dose.
B. Allometric scaling for immature clearance.
C. Hepatic adjustment.
D. Renal only.
Rationale: Immature renal/hepatic function requires 40-90 mg/kg/day divided; half-life 1-2h in neonates
vs. 1h adults. AAP antibiotic stewardship (2025).
, Question 9: Theophylline clearance decreases in heart failure due to:
A. Increased Vd.
B. Reduced hepatic blood flow.
C. Renal hyperfunction.
D. Protein binding.
Rationale: Low cardiac output halves clearance (half-life 9h → 25h), levels 5-15 mcg/mL. GINA asthma
(2025) favors alternatives due to PK variability.
Question 10: Bioavailability of oral morphine is:
A. 100%.
B. 20-30% due to first-pass.
C. 50%.
D. 80%.
Rationale: Extensive hepatic glucuronidation (UGT2B7) reduces F=24%; equipotent IV 3x oral. ASRA
opioid guidelines (2025) for PCA titration.
Question 11: In pregnancy, physiological PK changes include increased Vd for:
A. Lipophilic drugs (decreased).
B. Water-soluble drugs like aminoglycosides.
C. Protein-bound only.
D. Hepatic enzymes.
Rationale: Plasma volume +50% expands Vd (e.g., gentamicin 0.25 → 0.4 L/kg), requiring dose
increase. ACOG pharmacotherapy (2025).
Question 12: Steady-state for once-daily drug with 24h half-life is reached in:
A. 1 day.
B. 4-5 days (3.3 half-lives).
C. 24 hours.
D. 7 days.
Rationale: Css = (F × Dose / τ) / (1 - e^{-kτ}); 90% at 3-4 half-lives. Loading doses accelerate for
anticoagulants (ACC, 2025).
Question 13: Protein binding displacement interaction for warfarin by aspirin affects:
A. Vd.
B. Free fraction and anticoagulant effect.
C. Clearance.
D. Absorption.
