NR 565 ADVANCED PHARMACOLOGY FINAL EXAM REVIEW
2026/2027 | Already Rated A | Latest Chamberlain College
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UNIT 1: PHARMACOKINETICS & PHARMACODYNAMICS (15 Questions)
Q1: A 68-year-old male with atrial fibrillation is prescribed digoxin 0.25 mg daily. His
creatinine clearance is 45 mL/min (normal 90-120). He has hypoalbuminemia (albumin
2.8 g/dL). Which pharmacokinetic principle most significantly impacts his digoxin
dosing requirement?
A. Decreased volume of distribution requiring dose reduction
B. Increased hepatic metabolism necessitating enzyme induction monitoring
C. Reduced renal elimination requiring dose reduction and extended half-life
consideration [CORRECT]
D. Increased protein binding leading to higher free drug concentration
Correct Answer: C
Rationale: Digoxin is primarily eliminated unchanged by the kidneys (60-80%). With a
creatinine clearance of 45 mL/min, this patient has moderate renal impairment (Stage 3
CKD), significantly reducing digoxin clearance and extending its half-life from 36 hours
to approximately 60-100 hours. The loading dose may remain similar, but maintenance
dose should be reduced by 25-50% and given less frequently. While hypoalbuminemia
,affects highly protein-bound drugs, digoxin is only 20-30% protein-bound, making this
less clinically significant. Digoxin undergoes minimal hepatic metabolism. Option A is
incorrect because digoxin's Vd is large and primarily distributes to tissues, not
significantly affected by albumin. Option B is incorrect as digoxin is not a CYP
substrate. Option D is incorrect because digoxin's low protein binding makes this
clinically insignificant.
Q2: A 45-year-old female with epilepsy on phenytoin therapy presents with increased
seizure frequency. Her phenytoin level is 8 mcg/mL (therapeutic 10-20). She recently
started fluoxetine for depression. Which phenomenon explains this subtherapeutic
level?
A. Fluoxetine induces CYP2C9, increasing phenytoin metabolism
B. Competitive inhibition at the active site reduces phenytoin absorption
C. Fluoxetine inhibits CYP2C9, which should increase levels—suggesting nonadherence
or increased clearance [CORRECT]
D. Fluoxetine displaces phenytoin from albumin, increasing free fraction and elimination
Correct Answer: C
Rationale: This question requires analysis of expected versus observed outcomes.
Fluoxetine is a potent CYP2D6 inhibitor and moderate CYP2C9 inhibitor. Phenytoin is
metabolized primarily by CYP2C9 and CYP2C19. Inhibition should theoretically increase
phenytoin levels, not decrease them. The subtherapeutic level despite addition of an
inhibiting agent suggests either patient nonadherence, autoinduction completion
(phenytoin induces its own metabolism over weeks), or increased clearance from
,another mechanism. Option A is incorrect because fluoxetine inhibits, not induces, CYP
enzymes. Option B is incorrect as there's no significant absorption interaction. Option D
is partially true regarding protein binding displacement, but this would transiently
increase free drug and effect, not reduce total levels significantly.
Q3: A 72-year-old patient with heart failure has a drug with a half-life of 6 hours
prescribed for twice-daily dosing. How many days are required to reach approximately
97% of steady-state concentration?
A. 1 day
B. 1.5 days [CORRECT]
C. 3 days
D. 5 days
Correct Answer: B
Rationale: Steady state is reached in approximately 4-5 half-lives. At 4 half-lives, 94% of
steady state is achieved; at 5 half-lives, 97% is achieved. With a 6-hour half-life: 5 × 6
hours = 30 hours = 1.25 days, or approximately 1.5 days clinically. This principle is
crucial for drugs with narrow therapeutic indices where premature assessment of
therapeutic failure may lead to inappropriate dose escalation. Option A (1 day = 24
hours = 4 half-lives) achieves only 94%. Option C represents approximately 8 half-lives
(well beyond steady state). Option D represents excessive duration.
, Q4: Which pair of pharmacodynamic parameters best describes the relationship
between drug concentration at the receptor and clinical effect magnitude?
A. Emax and EC50 [CORRECT]
B. Kd and Ki
C. ED50 and LD50
D. Cmax and AUC
Correct Answer: A
Rationale: Emax (maximum effect achievable) and EC50 (concentration producing 50%
of maximum effect) are the fundamental parameters of the Emax model (Hill equation)
describing concentration-effect relationships. These parameters allow clinicians to
understand efficacy (Emax) and potency (EC50). Option B describes receptor binding
affinity and inhibition constants—pharmacologic but not clinical effect parameters.
Option C describes population-level dose-response and safety (therapeutic index), not
individual concentration-effect relationships. Option D describes pharmacokinetic
exposure parameters, not pharmacodynamic response.
Q5: A patient receiving a drug with high hepatic extraction ratio (ER > 0.7) develops
acute hepatitis. Which statement accurately describes the impact on drug bioavailability
and clearance?
A. Oral bioavailability decreases significantly due to reduced first-pass metabolism
B. Systemic clearance decreases proportionally to reduction in hepatic blood flow
2026/2027 | Already Rated A | Latest Chamberlain College
Guide | Pass Guaranteed
UNIT 1: PHARMACOKINETICS & PHARMACODYNAMICS (15 Questions)
Q1: A 68-year-old male with atrial fibrillation is prescribed digoxin 0.25 mg daily. His
creatinine clearance is 45 mL/min (normal 90-120). He has hypoalbuminemia (albumin
2.8 g/dL). Which pharmacokinetic principle most significantly impacts his digoxin
dosing requirement?
A. Decreased volume of distribution requiring dose reduction
B. Increased hepatic metabolism necessitating enzyme induction monitoring
C. Reduced renal elimination requiring dose reduction and extended half-life
consideration [CORRECT]
D. Increased protein binding leading to higher free drug concentration
Correct Answer: C
Rationale: Digoxin is primarily eliminated unchanged by the kidneys (60-80%). With a
creatinine clearance of 45 mL/min, this patient has moderate renal impairment (Stage 3
CKD), significantly reducing digoxin clearance and extending its half-life from 36 hours
to approximately 60-100 hours. The loading dose may remain similar, but maintenance
dose should be reduced by 25-50% and given less frequently. While hypoalbuminemia
,affects highly protein-bound drugs, digoxin is only 20-30% protein-bound, making this
less clinically significant. Digoxin undergoes minimal hepatic metabolism. Option A is
incorrect because digoxin's Vd is large and primarily distributes to tissues, not
significantly affected by albumin. Option B is incorrect as digoxin is not a CYP
substrate. Option D is incorrect because digoxin's low protein binding makes this
clinically insignificant.
Q2: A 45-year-old female with epilepsy on phenytoin therapy presents with increased
seizure frequency. Her phenytoin level is 8 mcg/mL (therapeutic 10-20). She recently
started fluoxetine for depression. Which phenomenon explains this subtherapeutic
level?
A. Fluoxetine induces CYP2C9, increasing phenytoin metabolism
B. Competitive inhibition at the active site reduces phenytoin absorption
C. Fluoxetine inhibits CYP2C9, which should increase levels—suggesting nonadherence
or increased clearance [CORRECT]
D. Fluoxetine displaces phenytoin from albumin, increasing free fraction and elimination
Correct Answer: C
Rationale: This question requires analysis of expected versus observed outcomes.
Fluoxetine is a potent CYP2D6 inhibitor and moderate CYP2C9 inhibitor. Phenytoin is
metabolized primarily by CYP2C9 and CYP2C19. Inhibition should theoretically increase
phenytoin levels, not decrease them. The subtherapeutic level despite addition of an
inhibiting agent suggests either patient nonadherence, autoinduction completion
(phenytoin induces its own metabolism over weeks), or increased clearance from
,another mechanism. Option A is incorrect because fluoxetine inhibits, not induces, CYP
enzymes. Option B is incorrect as there's no significant absorption interaction. Option D
is partially true regarding protein binding displacement, but this would transiently
increase free drug and effect, not reduce total levels significantly.
Q3: A 72-year-old patient with heart failure has a drug with a half-life of 6 hours
prescribed for twice-daily dosing. How many days are required to reach approximately
97% of steady-state concentration?
A. 1 day
B. 1.5 days [CORRECT]
C. 3 days
D. 5 days
Correct Answer: B
Rationale: Steady state is reached in approximately 4-5 half-lives. At 4 half-lives, 94% of
steady state is achieved; at 5 half-lives, 97% is achieved. With a 6-hour half-life: 5 × 6
hours = 30 hours = 1.25 days, or approximately 1.5 days clinically. This principle is
crucial for drugs with narrow therapeutic indices where premature assessment of
therapeutic failure may lead to inappropriate dose escalation. Option A (1 day = 24
hours = 4 half-lives) achieves only 94%. Option C represents approximately 8 half-lives
(well beyond steady state). Option D represents excessive duration.
, Q4: Which pair of pharmacodynamic parameters best describes the relationship
between drug concentration at the receptor and clinical effect magnitude?
A. Emax and EC50 [CORRECT]
B. Kd and Ki
C. ED50 and LD50
D. Cmax and AUC
Correct Answer: A
Rationale: Emax (maximum effect achievable) and EC50 (concentration producing 50%
of maximum effect) are the fundamental parameters of the Emax model (Hill equation)
describing concentration-effect relationships. These parameters allow clinicians to
understand efficacy (Emax) and potency (EC50). Option B describes receptor binding
affinity and inhibition constants—pharmacologic but not clinical effect parameters.
Option C describes population-level dose-response and safety (therapeutic index), not
individual concentration-effect relationships. Option D describes pharmacokinetic
exposure parameters, not pharmacodynamic response.
Q5: A patient receiving a drug with high hepatic extraction ratio (ER > 0.7) develops
acute hepatitis. Which statement accurately describes the impact on drug bioavailability
and clearance?
A. Oral bioavailability decreases significantly due to reduced first-pass metabolism
B. Systemic clearance decreases proportionally to reduction in hepatic blood flow
