, Question 1
A patient with heart failure with reduced ejection fraction (HFrEF) is initiated
on sacubitril/valsartan. Which mechanism best explains the need for a 36-hour
washout period when transitioning from an ACE inhibitor?
A. Prevention of bradykinin accumulation and angioedema
B. Avoidance of hyperkalemia from dual RAAS blockade
C. Reduction of hypotension from combined vasodilation
D. Prevention of renal function deterioration from prostaglandin
inhibition
Correct Answer: A - Prevention of bradykinin accumulation and
angioedema
RATIONALE
ACE inhibitors and sacubitril/valsartan both increase bradykinin;
concurrent use markedly raises angioedema risk, necessitating a
36-hour washout. Hyperkalemia, hypotension, and renal effects are
concerns but are not the primary reason for the washout.
Question 2
A patient receiving warfarin is prescribed trimethoprim-sulfamethoxazole for a
urinary tract infection. Which parameter requires the most immediate and
frequent monitoring?
A. Serum creatinine and potassium
B. INR and signs of bleeding
C. Platelet count and hemoglobin
D. Liver function tests and bilirubin
Correct Answer: B - INR and signs of bleeding
Page 2
, RATIONALE
Trimethoprim-sulfamethoxazole inhibits CYP2C9, reducing warfarin
metabolism and increasing INR/bleeding risk. While renal function
and potassium may be affected, the most critical immediate
monitoring is INR and bleeding signs.
Question 3
A patient with major depressive disorder is homozygous for CYP2D6 poor
metabolizer status. Which antidepressant is most likely to require a
significantly reduced dose or alternative therapy?
A. Sertraline
B. Fluoxetine
C. Venlafaxine
D. Bupropion
Correct Answer: C - Venlafaxine
RATIONALE
Venlafaxine is primarily metabolized by CYP2D6; poor metabolizers
have higher parent drug exposure and increased adverse effects.
Sertraline and fluoxetine are also CYP2D6 substrates but have more
complex metabolism; bupropion is primarily CYP2B6.
Question 4
Which pharmacokinetic parameter is most directly altered by advanced chronic
kidney disease (CrCl < 20 mL/min) when prescribing a drug that is 90%
renally eliminated?
A. Volume of distribution
B. Bioavailability
C. Elimination half-life
D. Protein binding
Correct Answer: C - Elimination half-life
Page 3
A patient with heart failure with reduced ejection fraction (HFrEF) is initiated
on sacubitril/valsartan. Which mechanism best explains the need for a 36-hour
washout period when transitioning from an ACE inhibitor?
A. Prevention of bradykinin accumulation and angioedema
B. Avoidance of hyperkalemia from dual RAAS blockade
C. Reduction of hypotension from combined vasodilation
D. Prevention of renal function deterioration from prostaglandin
inhibition
Correct Answer: A - Prevention of bradykinin accumulation and
angioedema
RATIONALE
ACE inhibitors and sacubitril/valsartan both increase bradykinin;
concurrent use markedly raises angioedema risk, necessitating a
36-hour washout. Hyperkalemia, hypotension, and renal effects are
concerns but are not the primary reason for the washout.
Question 2
A patient receiving warfarin is prescribed trimethoprim-sulfamethoxazole for a
urinary tract infection. Which parameter requires the most immediate and
frequent monitoring?
A. Serum creatinine and potassium
B. INR and signs of bleeding
C. Platelet count and hemoglobin
D. Liver function tests and bilirubin
Correct Answer: B - INR and signs of bleeding
Page 2
, RATIONALE
Trimethoprim-sulfamethoxazole inhibits CYP2C9, reducing warfarin
metabolism and increasing INR/bleeding risk. While renal function
and potassium may be affected, the most critical immediate
monitoring is INR and bleeding signs.
Question 3
A patient with major depressive disorder is homozygous for CYP2D6 poor
metabolizer status. Which antidepressant is most likely to require a
significantly reduced dose or alternative therapy?
A. Sertraline
B. Fluoxetine
C. Venlafaxine
D. Bupropion
Correct Answer: C - Venlafaxine
RATIONALE
Venlafaxine is primarily metabolized by CYP2D6; poor metabolizers
have higher parent drug exposure and increased adverse effects.
Sertraline and fluoxetine are also CYP2D6 substrates but have more
complex metabolism; bupropion is primarily CYP2B6.
Question 4
Which pharmacokinetic parameter is most directly altered by advanced chronic
kidney disease (CrCl < 20 mL/min) when prescribing a drug that is 90%
renally eliminated?
A. Volume of distribution
B. Bioavailability
C. Elimination half-life
D. Protein binding
Correct Answer: C - Elimination half-life
Page 3
