Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 1011: A patient treated for hypertension shows signs of hyperkalemia. Which class of antihypertensive agents is most likely to cause this side effect?

A. ACE inhibitors (Correct Answer)
B. Calcium channel blockers
C. Beta-blockers
D. Thiazide diuretics

Explanation: ***ACE inhibitors*** - **Angiotensin-converting enzyme (ACE) inhibitors** block the conversion of angiotensin I to angiotensin II, leading to decreased aldosterone secretion. - Reduced **aldosterone** levels decrease sodium reabsorption and potassium excretion in the renal tubules, resulting in **hyperkalemia**. *Calcium channel blockers* - **Calcium channel blockers** primarily work by causing vasodilation and reducing myocardial contractility. - They typically do not directly affect potassium levels and are not associated with **hyperkalemia**. *Beta-blockers* - **Beta-blockers** reduce heart rate and cardiac output by blocking beta-adrenergic receptors. - While they can cause slight shifts in potassium distribution, they are not a common cause of significant **hyperkalemia**. *Thiazide diuretics* - **Thiazide diuretics** inhibit sodium and chloride reabsorption in the distal convoluted tubule. - This promotes increased potassium excretion, leading to **hypokalemia**, not hyperkalemia.

Question 1012: Which of the following beta-blockers is cardioselective (beta-1 selective) and commonly used in the management of cardiovascular conditions?

A. Atenolol (Correct Answer)
B. Nadolol
C. Carvedilol
D. Propranolol

Explanation: ***Atenolol*** - **Atenolol** is a **beta-1 selective** adrenergic receptor antagonist, meaning it primarily blocks beta-1 receptors in the **heart**. - This **cardioselectivity** makes it particularly useful in cardiovascular conditions like hypertension, angina, and post-myocardial infarction, with potentially fewer respiratory side effects. *Nadolol* - **Nadolol** is a **non-selective beta-blocker** that blocks both beta-1 and beta-2 adrenergic receptors. - Its non-selectivity means it can cause **bronchoconstriction** and is generally avoided in patients with asthma or COPD. *Carvedilol* - **Carvedilol** is a **non-selective beta-blocker** with additional **alpha-1 blocking** properties. - It is often used in **heart failure** and hypertension due to its vasodilatory effects but is not strictly cardioselective. *Propranolol* - **Propranolol** is a classic example of a **non-selective beta-blocker** affecting both beta-1 and beta-2 receptors. - While effective for various cardiovascular conditions, its non-selectivity can lead to **bronchospasm** and other beta-2 mediated side effects.

Question 1013: Which direct oral anticoagulant (DOAC) is recommended as a first-line treatment for reducing the risk of stroke in patients with atrial fibrillation and has demonstrated a lower risk of major bleeding compared to warfarin?

A. Lisinopril
B. Atorvastatin
C. Rivaroxaban
D. Apixaban (Correct Answer)

Explanation: ***Apixaban*** - **Apixaban** is a **direct oral anticoagulant (DOAC)** widely recommended as a first-line agent for stroke prevention in non-valvular atrial fibrillation (AF). - The **ARISTOTLE trial** demonstrated that apixaban was superior to warfarin in reducing stroke/systemic embolism and had significantly **lower rates of major bleeding** and intracranial hemorrhage. - Its **twice-daily dosing** and favorable safety profile make it a preferred choice among DOACs. *Rivaroxaban* - **Rivaroxaban** is also a **DOAC** used for stroke prevention in atrial fibrillation. - While effective, the **ROCKET-AF trial** showed non-inferiority to warfarin but did not demonstrate the same reduction in major bleeding as apixaban. - It requires **once-daily dosing** and should be taken with food. *Lisinopril* - **Lisinopril** is an **ACE inhibitor** primarily used to treat hypertension and heart failure. - It does not have anticoagulant properties and does not directly reduce the risk of stroke in atrial fibrillation. *Atorvastatin* - **Atorvastatin** is a **statin medication** used to lower cholesterol and reduce the risk of atherosclerotic cardiovascular events. - It does not prevent cardioembolic stroke from atrial fibrillation; its primary role is in managing dyslipidemia.

Question 1014: Which class of antihypertensive drugs specifically targets the angiotensin II receptor to reduce blood pressure?

A. ACE inhibitors
B. Calcium channel blockers
C. Beta-blockers
D. Angiotensin receptor blockers (ARBs) (Correct Answer)

Explanation: ***Angiotensin receptor blockers (ARBs)*** - **ARBs** directly block the **angiotensin II type 1 (AT1) receptor**, preventing angiotensin II from binding and exerting its vasoconstrictive and aldosterone-stimulating effects [1]. - This specific blockade leads to vasodilation, reduced sodium and water retention, and ultimately, lower blood pressure [1]. *ACE inhibitors* - **ACE inhibitors** prevent the conversion of **angiotensin I to angiotensin II** by inhibiting the angiotensin-converting enzyme [2]. - While they also reduce angiotensin II activity, their mechanism is upstream from directly blocking the receptor [2]. *Calcium channel blockers* - **Calcium channel blockers** reduce blood pressure by blocking the influx of **calcium ions** into vascular smooth muscle and cardiac cells. - This leads to vasodilation and decreased cardiac contractility, a mechanism unrelated to the renin-angiotensin-aldosterone system (RAAS). *Beta-blockers* - **Beta-blockers** reduce blood pressure by blocking **beta-adrenergic receptors**, leading to decreased heart rate, reduced cardiac output, and inhibition of renin release [3]. - Their primary action is on the sympathetic nervous system and differs from directly targeting the angiotensin II receptor.

Question 1015: A 62-year-old patient with unstable angina is prescribed a drug to reduce myocardial oxygen demand. Which drug would be the best option?

A. Metoprolol (Correct Answer)
B. Rivaroxaban
C. Rosuvastatin
D. Captopril

Explanation: ***Metoprolol*** - As a **beta-blocker**, metoprolol **decreases heart rate** and **myocardial contractility**, thereby reducing **myocardial oxygen demand**. - This reduction in demand is crucial for managing unstable angina, where the oxygen supply is insufficient to meet demand. *Rivaroxaban* - Rivaroxaban is an **anticoagulant** that works by inhibiting Factor Xa, and its primary role is to prevent **thromboembolic events**, not to directly reduce myocardial oxygen demand. - While it may be used in coronary artery disease to prevent clot formation, it does not directly manage the **angina symptoms** by affecting heart rate or contractility. *Rosuvastatin* - Rosuvastatin is a **statin**, used to lower **cholesterol levels** and stabilize **atherosclerotic plaques**. - Its main function is to **prevent the progression of atherosclerosis** and reduce the risk of future cardiovascular events, not to acutely reduce myocardial oxygen demand for angina relief. *Captopril* - Captopril is an **ACE inhibitor** that primarily works by causing **vasodilation** and reducing **blood pressure**, which can decrease afterload and indirectly reduce myocardial oxygen demand. - However, **beta-blockers** like metoprolol are more direct and effective at reducing oxygen demand by significantly lowering heart rate and contractility, making them the preferred first-line treatment for this indication.

Question 1016: Which antihypertensive drug works by inhibiting the angiotensin-converting enzyme and reducing the production of angiotensin II?

A. Losartan
B. Amlodipine
C. Enalapril (Correct Answer)
D. Hydralazine

Explanation: ***Enalapril*** - **Enalapril** is an **ACE inhibitor** that specifically blocks the conversion of **angiotensin I** to **angiotensin II**, thereby reducing blood pressure. - This action leads to **vasodilation**, reduced **aldosterone secretion**, and decreased **sodium and water retention**. *Losartan* - **Losartan** is an **angiotensin receptor blocker (ARB)**, which works by *blocking* the binding of **angiotensin II** to its receptors, rather than inhibiting its production. - While it also reduces the effects of **angiotensin II**, its mechanism of action is distinct from **ACE inhibitors**. *Amlodipine* - **Amlodipine** is a **calcium channel blocker** that primarily causes **vasodilation** by inhibiting calcium influx into vascular smooth muscle cells. - It does not directly interact with the **renin-angiotensin-aldosterone system (RAAS)**. *Hydralazine* - **Hydralazine** is a **direct vasodilator** that acts primarily on arterial smooth muscle to cause relaxation, leading to a reduction in **peripheral vascular resistance**. - Its mechanism is independent of the **RAAS** and does not involve **angiotensin-converting enzyme**.

Question 1017: Verapamil belongs to which class of antiarrhythmic drugs?

A. Class I
B. Class II
C. Class III
D. Class IV (Correct Answer)

Explanation: ***Class IV*** Verapamil is a calcium channel blocker that primarily works by inhibiting L-type calcium channels [1]. Class IV antiarrhythmics, like verapamil and diltiazem, are used to slow conduction through the AV node and reduce heart rate, particularly in supraventricular tachycardias [1, 2]. *Class I* Class I antiarrhythmics are sodium channel blockers [2] that primarily affect the fast depolarization phase of the action potential in cardiac myocytes. These are further subdivided into Ia, Ib, and Ic based on their effects on repolarization and binding kinetics. *Class II* Class II antiarrhythmics are beta-blockers (e.g., propranolol, metoprolol) that reduce sympathetic activity on the heart. They primarily act by blocking beta-adrenergic receptors, leading to decreased heart rate and contractility. *Class III* Class III antiarrhythmics are potassium channel blockers that prolong repolarization and the effective refractory period. Examples include amiodarone, sotalol, and dofetilide.

Question 1018: Which medication is primarily used for chemical cardioversion in patients with atrial fibrillation?

A. Digoxin
B. Amiodarone (Correct Answer)
C. Metoprolol
D. Diltiazem

Explanation: ***Amiodarone*** - **Amiodarone** is a Class III antiarrhythmic agent effective for both rate and rhythm control in **atrial fibrillation**, commonly used for **chemical cardioversion**. - It works by blocking potassium channels, prolonging the **action potential duration** and **QT interval**, thereby restoring normal sinus rhythm. *Digoxin* - **Digoxin** is primarily used for **rate control** in atrial fibrillation, particularly in patients with heart failure or left ventricular dysfunction. - It does not effectively **cardiovert** the rhythm to sinus rhythm but rather slows the ventricular response. *Metoprolol* - **Metoprolol** is a **beta-blocker** primarily used for **rate control** in atrial fibrillation by slowing conduction through the AV node. - While it helps manage heart rate, it is not a first-line agent for **chemical cardioversion** to restore sinus rhythm. *Diltiazem* - **Diltiazem** is a **non-dihydropyridine calcium channel blocker** used for **rate control** in atrial fibrillation by blocking the AV nodal conduction. - Similar to metoprolol and digoxin, its main role is to control ventricular rate, not to **chemically cardiovert** to sinus rhythm.

Question 1019: Which class of drugs blocks endothelin receptors and is used as first-line therapy for pulmonary arterial hypertension?

A. Endothelin receptor antagonists (Correct Answer)
B. Beta-blockers
C. Calcium channel blockers
D. Phosphodiesterase-5 inhibitors

Explanation: ***Endothelin receptor antagonists*** - These drugs, such as **bosentan**, **ambrisentan**, and **macitentan**, specifically block the effects of endothelin, a potent **vasoconstrictor** and **smooth muscle proliferator**, leading to pulmonary vasodilation. - They are considered a **first-line therapy**, especially in patients with **WHO functional class II and III** pulmonary arterial hypertension (PAH). - These agents target the endothelin pathway, one of the three key pathways (endothelin, nitric oxide, prostacyclin) implicated in PAH pathophysiology. *Beta-blockers* - **Beta-blockers** are generally **contraindicated** in PAH because they can worsen right ventricular function and reduce cardiac output. - They are used to treat conditions like systemic hypertension or coronary artery disease, not PAH. *Calcium channel blockers* - While certain **calcium channel blockers** (e.g., nifedipine, diltiazem, amlodipine) are used in a small subset of PAH patients who are **vasoreactive** (respond positively to acute vasodilator testing), they do not block endothelin receptors. - Their use is limited to about 5-10% of patients with idiopathic PAH who demonstrate acute vasoreactivity. *Phosphodiesterase-5 inhibitors* - **Phosphodiesterase-5 (PDE5) inhibitors** like **sildenafil** and **tadalafil** are also first-line agents for PAH and are very effective, but they work by enhancing the nitric oxide pathway, **not by blocking endothelin receptors**. - These drugs enhance the effects of nitric oxide through increased cGMP, leading to **pulmonary vasodilation**.

Question 1020: A 45-year-old man with a history of hypertension is started on a new antihypertensive drug. Two weeks later, he reports a persistent dry cough. Which class of drug is most likely responsible for this adverse effect?

A. Angiotensin II receptor blockers
B. Beta-blockers
C. Calcium channel blockers
D. ACE inhibitors (Correct Answer)

Explanation: ***ACE inhibitors*** - **Angiotensin-converting enzyme (ACE) inhibitors** are well-known to cause a persistent, dry cough in about 5-20% of patients [1]. - This cough is believed to be mediated by the accumulation of **bradykinin** and other kinins in the respiratory tract [1, 3].*Angiotensin II receptor blockers* - **Angiotensin II receptor blockers (ARBs)** generally do not cause a dry cough [2]. - ARBs are often used as an alternative to ACE inhibitors in patients who develop a cough [1, 2].*Beta-blockers* - **Beta-blockers** are generally not associated with a dry cough. - They can, however, exacerbate or cause **bronchospasm** in susceptible individuals (e.g., asthmatics).*Calcium channel blockers* - **Calcium channel blockers** are not typically associated with a dry cough as a common side effect. - Some may cause **peripheral edema** or **gingival hyperplasia**, but not usually respiratory symptoms.

Practice by Chapter

Antihypertensive Agents

Practice Questions

Drugs for Heart Failure

Practice Questions

Antiarrhythmic Drugs

Practice Questions

Antianginal Agents

Practice Questions

Lipid-Lowering Drugs

Practice Questions

Anticoagulants and Antiplatelet Drugs

Practice Questions

Thrombolytic Agents

Practice Questions

Drugs Used in Pulmonary Hypertension

Practice Questions

Drugs Used in Shock

Practice Questions

Cardiovascular Effects of Non-Cardiovascular Drugs

Practice Questions

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