Pharmacology Quiz: Calcium Channel Blockers
20 questions · exam conditions
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Calcium Channel BlockersQuestion 1 of 20

A 72-year-old female with hypertension and NYHA Class III systolic heart failure (ejection fraction 30%) requires an additional agent for blood pressure control. Her current regimen includes lisinopril, carvedilol, and furosemide. Initiation of which of the following calcium channel blockers carries the highest risk of clinical decompensation?

Amlodipine
Felodipine
Nifedipine XL
Verapamil
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Pharmacology Quiz

Pharmacology Quiz: Calcium Channel Blockers

Practice Calcium Channel Blockers in Pharmacology with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Calcium Channel Blockers, giving you a quick way to practice the rules, question types, and explanations that matter most for Pharmacology.

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Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A 72-year-old female with hypertension and NYHA Class III systolic heart failure (ejection fraction 30%) requires an additional agent for blood pressure control. Her current regimen includes lisinopril, carvedilol, and furosemide. Initiation of which of the following calcium channel blockers carries the highest risk of clinical decompensation?

  1. Amlodipine
  2. Felodipine
  3. Nifedipine XL
  4. Verapamil (correct answer)
Explanation: Verapamil is a non-dihydropyridine calcium channel blocker with significant negative inotropic (decreased contractility) and chronotropic (decreased heart rate) effects. In a patient with pre-existing systolic heart failure, these effects can worsen cardiac output and lead to clinical decompensation. Dihydropyridines like amlodipine and felodipine have minimal effects on cardiac contractility and are generally considered safer if a calcium channel blocker is needed in this population.

Question 2

A 62-year-old patient on amlodipine for hypertension develops significant, pitting, bilateral lower extremity edema. This side effect is primarily caused by which of the following hemodynamic mechanisms?

  1. Increased capillary hydrostatic pressure from preferential precapillary arteriolar vasodilation. (correct answer)
  2. Systemic fluid retention due to a drug-induced reduction in glomerular filtration rate.
  3. Decreased plasma oncotic pressure resulting from drug-induced proteinuria.
  4. An IgE-mediated allergic reaction leading to increased systemic capillary permeability.
Explanation: Dihydropyridine calcium channel blockers like amlodipine cause potent vasodilation of precapillary arterioles but have minimal effect on postcapillary venules. This imbalance increases the hydrostatic pressure within the capillary bed, leading to extravasation of fluid into the interstitial space and causing peripheral edema. The other options describe incorrect mechanisms for this specific side effect.

Question 3

A 58-year-old male with hypertension is prescribed a calcium channel blocker. He returns a month later complaining of significant constipation, which is a new symptom for him. Which of the following drugs was most likely prescribed?

  1. Nifedipine
  2. Amlodipine
  3. Felodipine
  4. Verapamil (correct answer)
Explanation: Constipation is a well-known and common side effect of verapamil due to its effect on blocking L-type calcium channels in the smooth muscle of the gastrointestinal tract, leading to decreased motility. While diltiazem can also cause constipation, it is most pronounced with verapamil. Dihydropyridines (nifedipine, amlodipine, felodipine) are much less likely to cause this particular side effect.

Question 4

A 65-year-old woman being treated with a high-intensity statin for hyperlipidemia is diagnosed with hypertension. Her physician initiates a new medication. One month later, she presents with severe myalgia and weakness. Laboratory tests show a markedly elevated creatine kinase level, suggesting rhabdomyolysis. The new medication is most likely which of the following?

  1. Amlodipine
  2. Nifedipine
  3. Verapamil (correct answer)
  4. Hydrochlorothiazide
Explanation: Verapamil (and diltiazem) are potent inhibitors of the cytochrome P450 3A4 (CYP3A4) enzyme. Many statins, including simvastatin and atorvastatin, are metabolized by CYP3A4. Co-administration of verapamil can significantly increase statin levels, raising the risk of myopathy and rhabdomyolysis. Dihydropyridines like amlodipine and nifedipine are much weaker CYP3A4 inhibitors and are less likely to cause this interaction. Hydrochlorothiazide is not a significant CYP3A4 inhibitor.

Question 5

A 68-year-old male with a history of persistent atrial fibrillation and hypertension presents for follow-up. His ventricular rate is consistently 110-120 bpm and his blood pressure is 155/95 mmHg. He is not currently on any rate-controlling or antihypertensive agents. Which of the following is the most appropriate single agent to address both conditions?

  1. Amlodipine
  2. Diltiazem (correct answer)
  3. Lisinopril
  4. Nifedipine
Explanation: Diltiazem is a non-dihydropyridine calcium channel blocker that has effects on both vascular smooth muscle (lowering blood pressure) and the atrioventricular (AV) node (slowing conduction and controlling ventricular rate in atrial fibrillation). Amlodipine and nifedipine are dihydropyridines that primarily act on vascular smooth muscle and can cause reflex tachycardia, making them unsuitable for rate control. Lisinopril is an ACE inhibitor that lowers blood pressure but has no direct effect on heart rate control.

Question 6

The cardiac action potential in atrioventricular (AV) nodal cells is characterized by a slow upstroke (Phase 0) that is dependent on calcium influx. A non-dihydropyridine calcium channel blocker would exert its primary dromotropic effect by directly altering which phase?

  1. Slowing the rate of depolarization during Phase 0. (correct answer)
  2. Increasing the rapid repolarization during Phase 1.
  3. Shortening the plateau duration of Phase 2.
  4. Accelerating the final repolarization during Phase 3.
Explanation: The action potential of SA and AV nodal cells is dependent on the inward calcium current (I_Ca) for its depolarization phase (Phase 0). Non-dihydropyridine CCBs block these L-type calcium channels, reducing the slope and amplitude of Phase 0. This directly slows the conduction velocity (negative dromotropic effect) through the AV node. In contrast, ventricular myocyte Phase 0 is sodium-dependent.

Question 7

A 55-year-old male is initiated on immediate-release nifedipine for severe hypertension. His blood pressure improves, but he reports palpitations. An ECG confirms sinus tachycardia with a heart rate of 115 bpm. Which of the following best explains the physiological mechanism for this patient's tachycardia?

  1. Direct agonism of beta-1 adrenergic receptors in the sinoatrial node.
  2. Baroreceptor-mediated increase in sympathetic outflow due to peripheral vasodilation. (correct answer)
  3. Intrinsic sympathomimetic activity inherent to the dihydropyridine class of drugs.
  4. Blockade of cardiac M2 muscarinic receptors, leading to a vagolytic effect.
Explanation: Dihydropyridine calcium channel blockers like nifedipine are potent peripheral vasodilators. The resulting rapid drop in blood pressure is sensed by baroreceptors, triggering a compensatory reflex increase in sympathetic nervous system outflow. This leads to increased heart rate (tachycardia) and contractility. The other options describe incorrect mechanisms.

Question 8

A patient with severe aortic stenosis is noted to have a fixed cardiac output. Which of the following medications would be most dangerous to administer for co-existing hypertension in this patient?

  1. Amlodipine
  2. Felodipine
  3. Lisinopril
  4. Verapamil (correct answer)
Explanation: In severe aortic stenosis, cardiac output is relatively fixed and dependent on adequate preload and heart rate. Survival depends on maintaining systemic vascular resistance (SVR). Potent vasodilators can cause a precipitous drop in blood pressure and coronary perfusion. While dihydropyridines (Amlodipine, Felodipine) also cause vasodilation, verapamil is particularly dangerous because it not only reduces SVR but also has potent negative inotropic and chronotropic effects, which could critically compromise the already-impaired cardiac output.

Question 9

A patient with hypertension requires therapy with a calcium channel blocker. They have a history of second-degree atrioventricular block (Mobitz I). Which of the following agents would be the most appropriate choice?

  1. Verapamil
  2. Diltiazem
  3. Amlodipine (correct answer)
  4. Any non-dihydropyridine CCB is acceptable.
Explanation: Non-dihydropyridine calcium channel blockers (verapamil and diltiazem) suppress atrioventricular (AV) nodal conduction and are contraindicated in patients with pre-existing second- or third-degree AV block. Dihydropyridine calcium channel blockers, such as amlodipine, have minimal effect on AV conduction and are therefore a much safer choice for controlling hypertension in this patient.

Question 10

A patient with Prinzmetal (vasospastic) angina experiences episodes of chest pain at rest. The pathophysiology involves coronary artery spasm. Which of the following provides the most targeted mechanism for preventing these episodes?

  1. Verapamil, by decreasing myocardial contractility and heart rate.
  2. Amlodipine, by potently relaxing coronary arterial smooth muscle. (correct answer)
  3. Diltiazem, by slowing atrioventricular nodal conduction.
  4. Nifedipine, by causing reflex sympathetic stimulation of the heart.
Explanation: The primary goal in treating vasospastic angina is to prevent and relieve coronary artery spasm. Dihydropyridine calcium channel blockers like amlodipine and nifedipine are potent vasodilators of arterial smooth muscle, including the coronary arteries. This makes them highly effective for this condition. While non-dihydropyridines also cause coronary vasodilation, their primary benefits in other types of angina relate to decreasing myocardial oxygen demand (by reducing heart rate and contractility), which is not the principal mechanism needed for vasospastic angina.

Question 11

A 68-year-old male with a history of persistent atrial fibrillation and hypertension presents for follow-up. His ventricular rate is consistently 110-120 bpm and his blood pressure is 155/95 mmHg. He is not currently on any rate-controlling or antihypertensive agents. Which of the following is the most appropriate single agent to address both conditions?

  1. Amlodipine
  2. Diltiazem (correct answer)
  3. Lisinopril
  4. Nifedipine
Explanation: Diltiazem is a non-dihydropyridine calcium channel blocker that has effects on both vascular smooth muscle (lowering blood pressure) and the atrioventricular (AV) node (slowing conduction and controlling ventricular rate in atrial fibrillation). Amlodipine and nifedipine are dihydropyridines that primarily act on vascular smooth muscle and can cause reflex tachycardia, making them unsuitable for rate control. Lisinopril is an ACE inhibitor that lowers blood pressure but has no direct effect on heart rate control.

Question 12

A 55-year-old male is initiated on immediate-release nifedipine for severe hypertension. His blood pressure improves, but he reports palpitations. An ECG confirms sinus tachycardia with a heart rate of 115 bpm. Which of the following best explains the physiological mechanism for this patient's tachycardia?

  1. Direct agonism of beta-1 adrenergic receptors in the sinoatrial node.
  2. Baroreceptor-mediated increase in sympathetic outflow due to peripheral vasodilation. (correct answer)
  3. Intrinsic sympathomimetic activity inherent to the dihydropyridine class of drugs.
  4. Blockade of cardiac M2 muscarinic receptors, leading to a vagolytic effect.
Explanation: Dihydropyridine calcium channel blockers like nifedipine are potent peripheral vasodilators. The resulting rapid drop in blood pressure is sensed by baroreceptors, triggering a compensatory reflex increase in sympathetic nervous system outflow. This leads to increased heart rate (tachycardia) and contractility. The other options describe incorrect mechanisms.

Question 13

A 62-year-old patient on amlodipine for hypertension develops significant, pitting, bilateral lower extremity edema. This side effect is primarily caused by which of the following hemodynamic mechanisms?

  1. Increased capillary hydrostatic pressure from preferential precapillary arteriolar vasodilation. (correct answer)
  2. Systemic fluid retention due to a drug-induced reduction in glomerular filtration rate.
  3. Decreased plasma oncotic pressure resulting from drug-induced proteinuria.
  4. An IgE-mediated allergic reaction leading to increased systemic capillary permeability.
Explanation: Dihydropyridine calcium channel blockers like amlodipine cause potent vasodilation of precapillary arterioles but have minimal effect on postcapillary venules. This imbalance increases the hydrostatic pressure within the capillary bed, leading to extravasation of fluid into the interstitial space and causing peripheral edema. The other options describe incorrect mechanisms for this specific side effect.

Question 14

A patient with stable angina and hypertension is well-managed on metoprolol succinate. However, her blood pressure remains elevated at 150/92 mmHg. The addition of which of the following medications carries the highest risk of inducing symptomatic bradycardia or atrioventricular block?

  1. Nifedipine
  2. Amlodipine
  3. Diltiazem (correct answer)
  4. Chlorthalidone
Explanation: Combining a beta-blocker (metoprolol) with a non-dihydropyridine calcium channel blocker (diltiazem or verapamil) can lead to an additive suppression of both the sinoatrial (SA) and atrioventricular (AV) nodes. This significantly increases the risk of severe bradycardia, heart block, and decreased cardiac contractility. Dihydropyridines (nifedipine, amlodipine) have minimal effects on the SA/AV nodes and are a safer combination with beta-blockers. Chlorthalidone is a diuretic and does not have this interaction.

Question 15

When comparing the effects of nifedipine and diltiazem in treating chronic stable angina, which statement accurately describes their differential impact on the major determinants of myocardial oxygen demand (MVO2)?

  1. Nifedipine decreases MVO2 primarily by reducing heart rate, while diltiazem decreases MVO2 by reducing afterload.
  2. Both agents reduce MVO2 primarily by causing significant venodilation, which decreases cardiac preload.
  3. Diltiazem reduces MVO2 by decreasing afterload, heart rate, and contractility; nifedipine's reduction in afterload may be offset by reflex tachycardia. (correct answer)
  4. Nifedipine is more effective at reducing MVO2 because its potent peripheral vasodilation causes a greater decrease in afterload than diltiazem.
Explanation: Myocardial oxygen demand is determined by heart rate, contractility, and wall tension (related to afterload and preload). Diltiazem (a non-DHP) reduces all three: it decreases heart rate and contractility directly, and reduces afterload. Nifedipine (a DHP) potently reduces afterload, but the resulting reflex tachycardia can increase heart rate and contractility, partially or completely offsetting the benefit of afterload reduction on MVO2.

Question 16

A 58-year-old male with hypertension is prescribed a calcium channel blocker. He returns a month later complaining of significant constipation, which is a new symptom for him. Which of the following drugs was most likely prescribed?

  1. Nifedipine
  2. Amlodipine
  3. Felodipine
  4. Verapamil (correct answer)
Explanation: Constipation is a well-known and common side effect of verapamil due to its effect on blocking L-type calcium channels in the smooth muscle of the gastrointestinal tract, leading to decreased motility. While diltiazem can also cause constipation, it is most pronounced with verapamil. Dihydropyridines (nifedipine, amlodipine, felodipine) are much less likely to cause this particular side effect.

Question 17

A patient with hypertension requires therapy with a calcium channel blocker. They have a history of second-degree atrioventricular block (Mobitz I). Which of the following agents would be the most appropriate choice?

  1. Verapamil
  2. Diltiazem
  3. Amlodipine (correct answer)
  4. Any non-dihydropyridine CCB is acceptable.
Explanation: Non-dihydropyridine calcium channel blockers (verapamil and diltiazem) suppress atrioventricular (AV) nodal conduction and are contraindicated in patients with pre-existing second- or third-degree AV block. Dihydropyridine calcium channel blockers, such as amlodipine, have minimal effect on AV conduction and are therefore a much safer choice for controlling hypertension in this patient.

Question 18

A 51-year-old patient suffers a subarachnoid hemorrhage. To prevent delayed cerebral ischemia from vasospasm, a specific calcium channel blocker is administered. Which drug is used for this indication and what is the primary reason for its selection?

  1. Verapamil, due to its ability to reduce cerebral metabolic rate.
  2. Diltiazem, due to its intermediate effects on cardiac and vascular tissue.
  3. Nimodipine, due to its high lipid solubility and relative selectivity for cerebral arteries. (correct answer)
  4. Amlodipine, due to its long half-life providing sustained vasodilation.
Explanation: Nimodipine, a dihydropyridine calcium channel blocker, is specifically approved for preventing cerebral vasospasm following subarachnoid hemorrhage. Its high lipophilicity allows it to effectively cross the blood-brain barrier, and it demonstrates a somewhat greater effect on cerebral arteries compared to other peripheral arteries. The other agents are not the standard of care for this specific indication.

Question 19

The cardiac action potential in atrioventricular (AV) nodal cells is characterized by a slow upstroke (Phase 0) that is dependent on calcium influx. A non-dihydropyridine calcium channel blocker would exert its primary dromotropic effect by directly altering which phase?

  1. Slowing the rate of depolarization during Phase 0. (correct answer)
  2. Increasing the rapid repolarization during Phase 1.
  3. Shortening the plateau duration of Phase 2.
  4. Accelerating the final repolarization during Phase 3.
Explanation: The action potential of SA and AV nodal cells is dependent on the inward calcium current (I_Ca) for its depolarization phase (Phase 0). Non-dihydropyridine CCBs block these L-type calcium channels, reducing the slope and amplitude of Phase 0. This directly slows the conduction velocity (negative dromotropic effect) through the AV node. In contrast, ventricular myocyte Phase 0 is sodium-dependent.

Question 20

A patient with Prinzmetal (vasospastic) angina experiences episodes of chest pain at rest. The pathophysiology involves coronary artery spasm. Which of the following provides the most targeted mechanism for preventing these episodes?

  1. Verapamil, by decreasing myocardial contractility and heart rate.
  2. Amlodipine, by potently relaxing coronary arterial smooth muscle. (correct answer)
  3. Diltiazem, by slowing atrioventricular nodal conduction.
  4. Nifedipine, by causing reflex sympathetic stimulation of the heart.
Explanation: The primary goal in treating vasospastic angina is to prevent and relieve coronary artery spasm. Dihydropyridine calcium channel blockers like amlodipine and nifedipine are potent vasodilators of arterial smooth muscle, including the coronary arteries. This makes them highly effective for this condition. While non-dihydropyridines also cause coronary vasodilation, their primary benefits in other types of angina relate to decreasing myocardial oxygen demand (by reducing heart rate and contractility), which is not the principal mechanism needed for vasospastic angina.