, Question 1
A patient with heart failure and reduced ejection fraction (HFrEF) is initiated
on sacubitril/valsartan. Which pharmacodynamic mechanism best explains the
need to discontinue an ACE inhibitor 36 hours before starting this therapy?
A. Additive bradykinin accumulation from neprilysin inhibition and ACE
inhibition increases angioedema risk.
B. Sacubitril inhibits the metabolism of valsartan, causing toxic
accumulation.
C. ACE inhibitors reduce renal perfusion, which blunts the efficacy of
sacubitril.
D. Valsartan induces CYP2C9, accelerating ACE inhibitor clearance and
causing rebound hypertension.
Correct Answer: A - Additive bradykinin accumulation from
neprilysin inhibition and ACE inhibition increases angioedema
risk.
RATIONALE
Neprilysin inhibition by sacubitril and ACE inhibition both increase
bradykinin, and their overlap markedly raises angioedema risk; a
36-hour washout is required. Valsartan does not inhibit sacubitril
metabolism, and ACE inhibitors do not blunt sacubitril efficacy via
renal perfusion. Valsartan is not a CYP2C9 inducer.
Question 2
A patient on warfarin for atrial fibrillation is prescribed
trimethoprim-sulfamethoxazole for a urinary tract infection. Which mechanism
most likely explains the subsequent supratherapeutic INR?
A. CYP2C9 inhibition by trimethoprim plus displacement of warfarin
from albumin.
B. Induction of vitamin K epoxide reductase by sulfamethoxazole.
C. Increased renal clearance of vitamin K-dependent clotting factors.
Page 2
, D. Enhanced warfarin absorption due to altered gastric pH.
Correct Answer: A - CYP2C9 inhibition by trimethoprim plus
displacement of warfarin from albumin.
RATIONALE
Trimethoprim inhibits CYP2C9, reducing warfarin metabolism, and
sulfamethoxazole displaces warfarin from plasma proteins, both
increasing free warfarin and INR. Sulfamethoxazole does not induce
VKOR, renal clearance of clotting factors is not increased, and gastric
pH changes do not significantly enhance warfarin absorption.
Question 3
A patient with major depressive disorder and a history of poor response to
SSRIs is started on vortioxetine. Which receptor activity profile distinguishes
vortioxetine from standard SSRIs?
A. It is a selective serotonin reuptake inhibitor with additional 5-HT3,
5-HT7, and 5-HT1D antagonism and 5-HT1A agonism.
B. It is a serotonin-norepinephrine reuptake inhibitor with strong
muscarinic antagonism.
C. It is a monoamine oxidase inhibitor that selectively inhibits MAO-A.
D. It is a pure 5-HT2A antagonist with no effect on serotonin reuptake.
Correct Answer: A - It is a selective serotonin reuptake inhibitor
with additional 5-HT3, 5-HT7, and 5-HT1D antagonism and
5-HT1A agonism.
RATIONALE
Vortioxetine is a multimodal antidepressant that inhibits serotonin
reuptake and modulates multiple serotonin receptors (5-HT3, 5-HT7,
5-HT1D antagonism; 5-HT1A agonism). It is not an SNRI, MAOI, or
pure 5-HT2A antagonist; those profiles correspond to other drug
classes.
Page 3
, Question 4
A patient with type 2 diabetes and a history of heart failure is prescribed
empagliflozin. Which mechanism contributes most to its cardiovascular
benefit?
A. Inhibition of sodium-glucose cotransporter 2 in the proximal tubule,
promoting natriuresis and reducing cardiac preload.
B. Direct agonism of GLP-1 receptors, enhancing myocardial
contractility.
C. Blockade of sodium channels in the myocardium, preventing
arrhythmias.
D. Stimulation of insulin secretion from pancreatic beta cells.
Correct Answer: A - Inhibition of sodium-glucose cotransporter 2
in the proximal tubule, promoting natriuresis and reducing
cardiac preload.
RATIONALE
SGLT2 inhibitors reduce glucose reabsorption and promote
natriuresis, lowering preload and afterload, which contributes to heart
failure benefits. They do not agonize GLP-1 receptors, block
myocardial sodium channels, or stimulate insulin secretion; those
mechanisms belong to other drug classes.
Question 5
A patient with asthma is prescribed montelukast. Which statement best reflects
a critical safety consideration for this medication?
A. It carries a boxed warning for serious neuropsychiatric events,
including suicidality.
B. It is contraindicated in patients with aspirin-sensitive asthma.
C. It should be used as a rescue inhaler for acute bronchospasm.
D. It requires routine monitoring of liver function tests every 3 months.
Correct Answer: A - It carries a boxed warning for serious
Page 4
A patient with heart failure and reduced ejection fraction (HFrEF) is initiated
on sacubitril/valsartan. Which pharmacodynamic mechanism best explains the
need to discontinue an ACE inhibitor 36 hours before starting this therapy?
A. Additive bradykinin accumulation from neprilysin inhibition and ACE
inhibition increases angioedema risk.
B. Sacubitril inhibits the metabolism of valsartan, causing toxic
accumulation.
C. ACE inhibitors reduce renal perfusion, which blunts the efficacy of
sacubitril.
D. Valsartan induces CYP2C9, accelerating ACE inhibitor clearance and
causing rebound hypertension.
Correct Answer: A - Additive bradykinin accumulation from
neprilysin inhibition and ACE inhibition increases angioedema
risk.
RATIONALE
Neprilysin inhibition by sacubitril and ACE inhibition both increase
bradykinin, and their overlap markedly raises angioedema risk; a
36-hour washout is required. Valsartan does not inhibit sacubitril
metabolism, and ACE inhibitors do not blunt sacubitril efficacy via
renal perfusion. Valsartan is not a CYP2C9 inducer.
Question 2
A patient on warfarin for atrial fibrillation is prescribed
trimethoprim-sulfamethoxazole for a urinary tract infection. Which mechanism
most likely explains the subsequent supratherapeutic INR?
A. CYP2C9 inhibition by trimethoprim plus displacement of warfarin
from albumin.
B. Induction of vitamin K epoxide reductase by sulfamethoxazole.
C. Increased renal clearance of vitamin K-dependent clotting factors.
Page 2
, D. Enhanced warfarin absorption due to altered gastric pH.
Correct Answer: A - CYP2C9 inhibition by trimethoprim plus
displacement of warfarin from albumin.
RATIONALE
Trimethoprim inhibits CYP2C9, reducing warfarin metabolism, and
sulfamethoxazole displaces warfarin from plasma proteins, both
increasing free warfarin and INR. Sulfamethoxazole does not induce
VKOR, renal clearance of clotting factors is not increased, and gastric
pH changes do not significantly enhance warfarin absorption.
Question 3
A patient with major depressive disorder and a history of poor response to
SSRIs is started on vortioxetine. Which receptor activity profile distinguishes
vortioxetine from standard SSRIs?
A. It is a selective serotonin reuptake inhibitor with additional 5-HT3,
5-HT7, and 5-HT1D antagonism and 5-HT1A agonism.
B. It is a serotonin-norepinephrine reuptake inhibitor with strong
muscarinic antagonism.
C. It is a monoamine oxidase inhibitor that selectively inhibits MAO-A.
D. It is a pure 5-HT2A antagonist with no effect on serotonin reuptake.
Correct Answer: A - It is a selective serotonin reuptake inhibitor
with additional 5-HT3, 5-HT7, and 5-HT1D antagonism and
5-HT1A agonism.
RATIONALE
Vortioxetine is a multimodal antidepressant that inhibits serotonin
reuptake and modulates multiple serotonin receptors (5-HT3, 5-HT7,
5-HT1D antagonism; 5-HT1A agonism). It is not an SNRI, MAOI, or
pure 5-HT2A antagonist; those profiles correspond to other drug
classes.
Page 3
, Question 4
A patient with type 2 diabetes and a history of heart failure is prescribed
empagliflozin. Which mechanism contributes most to its cardiovascular
benefit?
A. Inhibition of sodium-glucose cotransporter 2 in the proximal tubule,
promoting natriuresis and reducing cardiac preload.
B. Direct agonism of GLP-1 receptors, enhancing myocardial
contractility.
C. Blockade of sodium channels in the myocardium, preventing
arrhythmias.
D. Stimulation of insulin secretion from pancreatic beta cells.
Correct Answer: A - Inhibition of sodium-glucose cotransporter 2
in the proximal tubule, promoting natriuresis and reducing
cardiac preload.
RATIONALE
SGLT2 inhibitors reduce glucose reabsorption and promote
natriuresis, lowering preload and afterload, which contributes to heart
failure benefits. They do not agonize GLP-1 receptors, block
myocardial sodium channels, or stimulate insulin secretion; those
mechanisms belong to other drug classes.
Question 5
A patient with asthma is prescribed montelukast. Which statement best reflects
a critical safety consideration for this medication?
A. It carries a boxed warning for serious neuropsychiatric events,
including suicidality.
B. It is contraindicated in patients with aspirin-sensitive asthma.
C. It should be used as a rescue inhaler for acute bronchospasm.
D. It requires routine monitoring of liver function tests every 3 months.
Correct Answer: A - It carries a boxed warning for serious
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