Cardiovascular Pathopharmacology
1. A patient with heart failure with reduced ejection fraction (HFrEF) is
started on sacubitril/valsartan (Entresto). The patient is currently taking
lisinopril. What is the most important action prior to initiating the new
medication?
A) Stop the lisinopril immediately and start sacubitril/valsartan.
B) Stop the lisinopril and wait at least 36 hours before starting
sacubitril/valsartan.
C) Reduce the lisinopril dose by half while initiating sacubitril/valsartan.
D) Continue the lisinopril and add sacubitril/valsartan at a low dose.
Answer: B
Rationale: Sacubitril/valsartan is an ARNI. Concurrent use with an ACE
inhibitor (lisinopril) exponentially increases the risk of severe
angioedema. Guidelines mandate a 36-hour washout period between
stopping an ACE inhibitor and starting an ARNI.
2. A patient is prescribed amiodarone for persistent atrial fibrillation.
Which baseline assessment is critical due to the drug's severe adverse
effect profile?
A) Liver function tests and ophthalmologic exam
B) Pulmonary function tests and thyroid function tests
,C) Echocardiogram and stress test
D) Renal biopsy and auditory testing
Answer: B
Rationale: Amiodarone is highly lipophilic and contains iodine. It carries
a Black Box Warning for pulmonary toxicity (potentially fatal) and can
cause both hyper- and hypothyroidism due to its iodine load.
3. A patient taking digoxin for heart failure presents with nausea,
vomiting, and a heart rate of 48 bpm. Their serum potassium is 2.8
mEq/L. What is the pathophysiological mechanism exacerbating this
patient's condition?
A) Hyperkalemia increases digoxin receptor affinity.
B) Hypokalemia increases the binding of digoxin to the Na+/K+ ATPase
pump, increasing toxicity.
C) Hypokalemia decreases the absorption of digoxin in the GI tract.
D) Hyperkalemism antagonizes the effects of digoxin at the myocardial
cellular level.
Answer: B
Rationale: Digoxin works by inhibiting the Na+/K+ ATPase pump.
Hypokalemia (often from concurrent diuretic use) allows digoxin to bind
more tightly to this pump, significantly increasing the risk of digoxin
toxicity (which presents as GI distress, bradycardia, and visual
disturbances).
,4. Which physiologic mechanism explains why ACE inhibitors are
preferred over ARBs in the management of heart failure, particularly in
the early stages?
A) ACE inhibitors prevent the breakdown of bradykinin, causing
vasodilation.
B) ACE inhibitors block the AT1 receptor directly, preventing
vasoconstriction.
C) ACE inhibitors increase the circulating levels of angiotensin II.
D) ACE inhibitors increase the degradation of aldosterone.
Answer: A
Rationale: ACE inhibitors block the conversion of ATI to ATII, but they
also prevent the breakdown of bradykinin. Increased bradykinin causes
vasodilation, which is beneficial in HF. (Note: This is also the cause of
the "ACE inhibitor cough").
5. A patient with hyperlipidemia is prescribed niacin. The patient
reports intense flushing and itching after taking the medication. What is
the recommended pharmacologic intervention to manage this adverse
effect?
A) Take niacin on an empty stomach.
B) Administer aspirin 30 minutes before taking niacin.
C) Switch to a high-dose statin immediately.
D) Take niacin with a high-fat meal.
Answer: B
, Rationale: Niacin-induced flushing is mediated by prostaglandin D2
release. Taking an aspirin (an NSAID/prostaglandin inhibitor) 30 minutes
prior to the niacin dose significantly reduces this side effect.
6. A patient is started on hydralazine and isosorbide dinitrate for HFrEF.
What is the primary pathopharmacological rationale for combining
these two specific drugs?
A) They both decrease afterload by blocking calcium channels.
B) The combination provides balanced arterial and venous vasodilation,
reducing preload and afterload.
C) They synergistically increase myocardial contractility.
D) The combination prevents reflex tachycardia associated with
hydralazine.
Answer: B
Rationale: Hydralazine primarily causes arterial vasodilation (decreasing
afterload), while nitrates cause venous vasodilation (decreasing
preload). This combination is particularly useful in patients who cannot
tolerate ACE inhibitors/ARNIs.
7. A patient taking warfarin for atrial fibrillation is newly prescribed
amiodarone. The provider must adjust the warfarin dose. What is the
pharmacokinetic reason for this interaction?
A) Amiodarone induces CYP450 enzymes, increasing warfarin
metabolism.
1. A patient with heart failure with reduced ejection fraction (HFrEF) is
started on sacubitril/valsartan (Entresto). The patient is currently taking
lisinopril. What is the most important action prior to initiating the new
medication?
A) Stop the lisinopril immediately and start sacubitril/valsartan.
B) Stop the lisinopril and wait at least 36 hours before starting
sacubitril/valsartan.
C) Reduce the lisinopril dose by half while initiating sacubitril/valsartan.
D) Continue the lisinopril and add sacubitril/valsartan at a low dose.
Answer: B
Rationale: Sacubitril/valsartan is an ARNI. Concurrent use with an ACE
inhibitor (lisinopril) exponentially increases the risk of severe
angioedema. Guidelines mandate a 36-hour washout period between
stopping an ACE inhibitor and starting an ARNI.
2. A patient is prescribed amiodarone for persistent atrial fibrillation.
Which baseline assessment is critical due to the drug's severe adverse
effect profile?
A) Liver function tests and ophthalmologic exam
B) Pulmonary function tests and thyroid function tests
,C) Echocardiogram and stress test
D) Renal biopsy and auditory testing
Answer: B
Rationale: Amiodarone is highly lipophilic and contains iodine. It carries
a Black Box Warning for pulmonary toxicity (potentially fatal) and can
cause both hyper- and hypothyroidism due to its iodine load.
3. A patient taking digoxin for heart failure presents with nausea,
vomiting, and a heart rate of 48 bpm. Their serum potassium is 2.8
mEq/L. What is the pathophysiological mechanism exacerbating this
patient's condition?
A) Hyperkalemia increases digoxin receptor affinity.
B) Hypokalemia increases the binding of digoxin to the Na+/K+ ATPase
pump, increasing toxicity.
C) Hypokalemia decreases the absorption of digoxin in the GI tract.
D) Hyperkalemism antagonizes the effects of digoxin at the myocardial
cellular level.
Answer: B
Rationale: Digoxin works by inhibiting the Na+/K+ ATPase pump.
Hypokalemia (often from concurrent diuretic use) allows digoxin to bind
more tightly to this pump, significantly increasing the risk of digoxin
toxicity (which presents as GI distress, bradycardia, and visual
disturbances).
,4. Which physiologic mechanism explains why ACE inhibitors are
preferred over ARBs in the management of heart failure, particularly in
the early stages?
A) ACE inhibitors prevent the breakdown of bradykinin, causing
vasodilation.
B) ACE inhibitors block the AT1 receptor directly, preventing
vasoconstriction.
C) ACE inhibitors increase the circulating levels of angiotensin II.
D) ACE inhibitors increase the degradation of aldosterone.
Answer: A
Rationale: ACE inhibitors block the conversion of ATI to ATII, but they
also prevent the breakdown of bradykinin. Increased bradykinin causes
vasodilation, which is beneficial in HF. (Note: This is also the cause of
the "ACE inhibitor cough").
5. A patient with hyperlipidemia is prescribed niacin. The patient
reports intense flushing and itching after taking the medication. What is
the recommended pharmacologic intervention to manage this adverse
effect?
A) Take niacin on an empty stomach.
B) Administer aspirin 30 minutes before taking niacin.
C) Switch to a high-dose statin immediately.
D) Take niacin with a high-fat meal.
Answer: B
, Rationale: Niacin-induced flushing is mediated by prostaglandin D2
release. Taking an aspirin (an NSAID/prostaglandin inhibitor) 30 minutes
prior to the niacin dose significantly reduces this side effect.
6. A patient is started on hydralazine and isosorbide dinitrate for HFrEF.
What is the primary pathopharmacological rationale for combining
these two specific drugs?
A) They both decrease afterload by blocking calcium channels.
B) The combination provides balanced arterial and venous vasodilation,
reducing preload and afterload.
C) They synergistically increase myocardial contractility.
D) The combination prevents reflex tachycardia associated with
hydralazine.
Answer: B
Rationale: Hydralazine primarily causes arterial vasodilation (decreasing
afterload), while nitrates cause venous vasodilation (decreasing
preload). This combination is particularly useful in patients who cannot
tolerate ACE inhibitors/ARNIs.
7. A patient taking warfarin for atrial fibrillation is newly prescribed
amiodarone. The provider must adjust the warfarin dose. What is the
pharmacokinetic reason for this interaction?
A) Amiodarone induces CYP450 enzymes, increasing warfarin
metabolism.
