Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 1151: Hyperkalemia is associated with:

A. Thiazide diuretics (e.g., Chlorthalidone)
B. Antiarrhythmic agents (e.g., Amiodarone)
C. Angiotensin-converting enzyme (ACE) inhibitors (Correct Answer)
D. Loop diuretics (e.g., Furosemide)

Explanation: ***Angiotensin-converting enzyme (ACE) inhibitors*** - **ACE inhibitors** block the conversion of **angiotensin I to angiotensin II**, which reduces **aldosterone** secretion. - Reduced **aldosterone** leads to decreased **potassium excretion** in the kidneys, causing **potassium retention** and potentially **hyperkalemia**. - This is a well-known adverse effect, especially in patients with **renal impairment** or when combined with **potassium-sparing diuretics** or **potassium supplements**. *Thiazide diuretics (e.g., Chlorthalidone)* - **Thiazide diuretics** work by inhibiting the **sodium-chloride cotransporter** in the **distal convoluted tubule**, increasing sodium and water excretion. - This action typically leads to **hypokalemia** by increasing **potassium excretion**, not hyperkalemia. *Loop diuretics (e.g., Furosemide)* - **Loop diuretics** inhibit the **Na-K-2Cl cotransporter** in the **thick ascending limb of the loop of Henle**. - They are potent **potassium-wasting diuretics** that cause **hypokalemia** through increased renal potassium excretion, not hyperkalemia. *Antiarrhythmic agents (e.g., Amiodarone)* - **Amiodarone** is an antiarrhythmic agent that primarily acts by blocking **potassium channels** and has complex electrophysiological effects. - It is not directly associated with causing **hyperkalemia**; its primary electrolyte-related side effects involve thyroid function, not potassium homeostasis.

Question 1152: In a patient diagnosed with pheochromocytoma, what is the appropriate preoperative pharmacological management to control hypertension before surgery?

A. Phenoxybenzamine and propranolol (Correct Answer)
B. Propranolol
C. Nitroglycerine
D. Phentolamine

Explanation: ***Phenoxybenzamine and propranolol*** - **Phenoxybenzamine** (an **irreversible** non-selective **alpha-blocker**) is initiated first to prevent hypertensive crises during surgery by blocking the effects of catecholamines on blood vessels. - **Propranolol** (a **beta-blocker**) is added after adequate alpha-blockade to control **tachycardia** and arrhythmias, as blocking only alpha-receptors can lead to unopposed beta-adrenergic stimulation. *Phentolamine (short-acting alpha blocker)* - While **phentolamine** is an alpha-blocker, it is typically used for **intraoperative management** of hypertensive crises or for short-term control, not as the primary preoperative preparation. - It is a **reversible** blocker and does not provide the sustained, robust alpha-blockade required for safe preoperative management of pheochromocytoma. *Propranolol (beta-blocker)* - **Beta-blockers** alone should **never be started first** in pheochromocytoma because blocking beta-2 receptors (which mediate vasodilation) in the presence of high circulating catecholamines can lead to **unopposed alpha-adrenergic vasoconstriction**, causing a dangerous hypertensive crisis. - It is only added after adequate alpha-blockade has been achieved to manage **tachycardia**. *Nitroglycerine (vasodilator)* - **Nitroglycerine** is primarily a **venodilator** and is used to relieve angina or manage acute hypertensive emergencies, not for the chronic preoperative management of pheochromocytoma. - It does not address the underlying pathophysiology of excessive catecholamine release and can lead to reflex **tachycardia**.

Question 1153: Which calcium channel blocker is known to cause reflex tachycardia?

A. Nifedipine (Correct Answer)
B. Verapamil
C. Amlodipine
D. Diltiazem

Explanation: ***Nifedipine*** - **Nifedipine** is a **dihydropyridine calcium channel blocker** that causes significant **peripheral vasodilation**. - This rapid drop in blood pressure activates the **baroreceptor reflex**, leading to an increase in heart rate (**reflex tachycardia**) to compensate. *Verapamil* - **Verapamil** is a **non-dihydropyridine calcium channel blocker** that acts on both vascular smooth muscle and cardiac conduction. - It has a direct negative chronotropic effect on the heart, which typically **prevents reflex tachycardia**. *Amlodipine* - **Amlodipine** is a **long-acting dihydropyridine calcium channel blocker** with a more gradual onset of action. - While it causes peripheral vasodilation, its **slow onset and prolonged duration** of action typically result in less pronounced or absent reflex tachycardia compared to nifedipine. *Diltiazem* - **Diltiazem** is a **non-dihydropyridine calcium channel blocker** with effects on both the heart and peripheral vasculature. - Similar to verapamil, its direct **negative chronotropic and dromotropic effects** on the heart prevent significant reflex tachycardia.

Question 1154: Which of the following enzymes is not targeted by hypolipidemic drugs?

A. HMG Co A reductase
B. Lipoprotein lipase
C. Acyl CoA, cholesterol acyl transferase 1
D. Peripheral decarboxylase (Correct Answer)

Explanation: ***Peripheral decarboxylase*** - **Peripheral decarboxylase** (also known as DOPA decarboxylase) is involved in the synthesis of dopamine from L-DOPA and is a target for drugs used in **Parkinson's disease**, not hypolipidemic drugs. - Its inhibition by drugs like **carbidopa** or **benserazide** prevents the peripheral conversion of L-DOPA to dopamine, increasing L-DOPA availability for the brain. *HMG Co A reductase* - **HMG-CoA reductase** is the rate-limiting enzyme in cholesterol biosynthesis and is the primary target for **statins** (e.g., atorvastatin, simvastatin). - Statins effectively lower **LDL cholesterol** by inhibiting this enzyme, reducing endogenous cholesterol production. *Lipoprotein lipase* - **Lipoprotein lipase (LPL)** activity can be enhanced by certain hypolipidemic drugs, such as **fibrates**, which activate **PPAR-α**. - Increased LPL activity leads to enhanced hydrolysis of **triglycerides** from VLDL and chylomicrons, reducing triglyceride levels in plasma. *Acyl CoA, cholesterol acyl transferase 1* - **Acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors** were developed as potential hypolipidemic agents to prevent cholesterol esterification and absorption. - While not widely used clinically due to efficacy and side effect profiles, **ACAT1** is involved in cholesterol esterification in the intestine and liver, making it a target for reducing cholesterol absorption.

Question 1155: In a diabetic patient with hypertension, which of the following medications is the most suitable choice for management?

A. Enalapril (Correct Answer)
B. Clonidine
C. Hydrochlorothiazide
D. Propranolol

Explanation: ***Enalapril*** - **ACE inhibitors** like enalapril are first-line agents in diabetic patients with hypertension due to their **renoprotective effects**, slowing the progression of **diabetic nephropathy**. - They reduce **glomerular pressure** and **albuminuria**, which is crucial in managing long-term complications of diabetes. *Propranolol* - **Beta-blockers** like propranolol can mask symptoms of **hypoglycemia** (e.g., tremors, palpitations), which is a significant concern in diabetic patients. - They may also worsen **insulin resistance** and negatively impact the lipid profile. *Clonidine* - **Clonidine**, an alpha-2 agonist, is typically reserved for **resistant hypertension** or specific conditions like **ADHD** due to its side effects. - It can cause significant **sedation**, **dry mouth**, and **rebound hypertension** upon sudden discontinuation, making it less suitable for routine management. *Hydrochlorothiazide* - **Thiazide diuretics** can cause adverse metabolic effects in diabetic patients, including **hyperglycemia** and worsening of **insulin resistance**. - While effective for hypertension, their metabolic profile makes them less preferred as a first-line agent in patients with diabetes.

Question 1156: Which of the following drugs lack vasodilatory properties but are effective in angina?

A. Metoprolol (Correct Answer)
B. Isosorbide dinitrate
C. Nifedipine
D. Verapamil

Explanation: ***Metoprolol*** - **Metoprolol** is a beta-blocker that reduces myocardial oxygen demand by decreasing heart rate, contractility, and blood pressure, without direct vasodilatory effects. - Its efficacy in angina is primarily due to these **cardiac depressant actions**, which relieve myocardial ischemia. *Isosorbide dinitrate* - **Isosorbide dinitrate** is a nitrate that works by releasing nitric oxide, leading to **venodilation** and **arterial dilation**, particularly reducing preload and improving coronary blood flow. - Its anti-anginal effect is directly linked to its **vasodilatory properties**. *Nifedipine* - **Nifedipine** is a dihydropyridine calcium channel blocker that produces potent **vasodilation** of both coronary and peripheral arteries. - Its primary mechanism of action in angina involves **reducing afterload** and improving coronary blood flow through vasodilation. *Verapamil* - **Verapamil** is a non-dihydropyridine calcium channel blocker that causes **coronary and peripheral vasodilation**, reducing afterload and improving myocardial perfusion. - While it also reduces heart rate and contractility, its direct **vasodilatory effects** contribute significantly to its anti-anginal action.

Question 1157: All drugs decrease mortality in heart failure except:

A. Enalapril
B. Metoprolol
C. Digoxin (Correct Answer)
D. Telmisartan

Explanation: ***Digoxin*** - **Digoxin** is known to improve symptoms and reduce hospitalizations in heart failure, but it has **not been shown to decrease mortality** in large clinical trials (DIG trial). - Its narrow **therapeutic window** and potential for toxicity, especially in patients with renal impairment, limit its use primarily to symptom management. *Metoprolol* - **Metoprolol succinate**, a beta-blocker, significantly reduces mortality and morbidity in patients with chronic heart failure with reduced ejection fraction (MERIT-HF trial) by blocking the deleterious effects of the sympathetic nervous system. - It works by reducing heart rate, myocardial oxygen demand, and cardiac remodeling. *Enalapril* - **Enalapril**, an ACE inhibitor, is a cornerstone medication in heart failure treatment due to its proven ability to reduce mortality, hospitalizations, and improve quality of life (CONSENSUS, SOLVD trials). - It works by blocking the **renin-angiotensin-aldosterone system**, leading to vasodilation, reduced preload and afterload, and prevention of cardiac remodeling. *Telmisartan* - **Telmisartan**, an ARB (angiotensin receptor blocker), is used as an alternative in heart failure patients who cannot tolerate ACE inhibitors due to side effects like cough. - ARBs as a class have shown mortality benefits in heart failure, acting by blocking the **angiotensin II type 1 receptor**, producing similar cardiovascular benefits to ACE inhibitors in terms of vasodilation and reduction in cardiac remodeling.

Question 1158: Which of the following drugs has the LEAST cardiac side effects when used for treating an acute attack of asthma in a cardiovascular patient?

A. Salbutamol (short-acting beta-agonist)
B. Terbutaline (short-acting beta-agonist)
C. Ipratropium (short-acting anticholinergic) (Correct Answer)
D. Formoterol (long-acting beta-agonist)

Explanation: ***Ipratropium (short-acting anticholinergic)*** - Ipratropium is a **bronchodilator** that acts as an **anticholinergic** via **M3 muscarinic receptor antagonism** in the airways. - It has **minimal systemic absorption** and produces **no direct cardiac stimulation**, making it the option with the least cardiovascular side effects. - While typically used as an **adjunct to beta-agonists** in acute asthma, it has the most favorable cardiac safety profile among bronchodilators. - Particularly useful in patients with **severe cardiovascular disease** where minimizing cardiac stimulation is crucial. *Salbutamol (short-acting beta-agonist)* - Salbutamol is a **selective beta-2 adrenergic agonist** and the first-line treatment for acute asthma. - Despite beta-2 selectivity, it can have **off-target effects on cardiac beta-1 receptors**, potentially causing tachycardia, palpitations, and increased myocardial oxygen demand. - At therapeutic doses, cardiac effects are usually mild and acceptable even in cardiovascular patients, but more pronounced than ipratropium. *Terbutaline (short-acting beta-agonist)* - Terbutaline is a **beta-2 agonist** with similar cardiac risk profile to salbutamol. - Can cause **tachycardia and arrhythmias** due to non-specific beta-adrenergic activation, particularly at higher doses or in sensitive patients. - Effective for acute bronchodilation but produces more cardiac stimulation than anticholinergics. *Formoterol (long-acting beta-agonist)* - Formoterol is a **long-acting beta-2 agonist (LABA)** with rapid onset but prolonged duration of action. - **Not recommended for acute asthma attacks** as monotherapy; LABAs are maintenance medications. - Has potential for significant **cardiac side effects** including palpitations, tremor, and arrhythmias due to prolonged beta-adrenergic stimulation. - Carries greater cardiovascular risk than short-acting agents due to extended systemic exposure.

Question 1159: Which drug used for the common cold has been associated with an increased risk of stroke?

A. Diphenhydramine
B. Phenylephrine
C. Pseudoephedrine (Correct Answer)
D. Oxymetazoline

Explanation: ***Pseudoephedrine*** - Pseudoephedrine is a **sympathomimetic** that can cause **vasoconstriction**, leading to increased blood pressure and heart rate, which elevates the risk of stroke, especially in susceptible individuals [1, 2, 3]. - Its mechanism of action involves stimulating **alpha- and beta-adrenergic receptors**, producing systemic vasoconstriction that reduces nasal congestion [1]. - **FDA restrictions** were placed on pseudoephedrine sales due to well-documented cardiovascular risks, including **hemorrhagic stroke**, particularly in young women and patients with uncontrolled hypertension [3].*Phenylephrine* - Phenylephrine is also a **sympathomimetic decongestant**, primarily an **alpha-1 adrenergic agonist**, causing vasoconstriction [3]. - While it can theoretically increase blood pressure, its **oral bioavailability is poor** (approximately 38%) due to extensive first-pass metabolism, resulting in less consistent systemic effects compared to pseudoephedrine. - The stroke risk association is **significantly lower** than pseudoephedrine, making it a preferred alternative in many guidelines.*Diphenhydramine* - Diphenhydramine is an **antihistamine with anticholinergic properties** used for allergy symptoms and sedation, not primarily as a decongestant. - It does not have a direct mechanism of action that significantly increases the risk of stroke through vasoconstriction. - May cause drowsiness and anticholinergic side effects, but not associated with acute cardiovascular events like stroke.*Oxymetazoline* - Oxymetazoline is a **topical decongestant** found in nasal sprays, which acts as a direct **alpha-adrenergic agonist**. - While it causes local vasoconstriction, systemic absorption is **minimal with topical use**, and it is less associated with stroke risk compared to oral decongestants like pseudoephedrine. - Main concern is **rebound congestion** (rhinitis medicamentosa) with prolonged use, not cardiovascular events.

Question 1160: How much decrease in LDL cholesterol and how much increase in HDL cholesterol can occur with the use of bile acid resins as anti-dyslipidemic drugs?

A. 15-25% decrease in LDL-C and 3-5% increase in HDL-C (Correct Answer)
B. 3-5% decrease in LDL-C and 1-3% increase in HDL-C
C. 25-35% decrease in LDL-C and 1-3% increase in HDL-C
D. 5-10% decrease in LDL-C and 1-3% increase in HDL-C

Explanation: ***Correct: 15-25% decrease in LDL-C and 3-5% increase in HDL-C***- **Bile acid resins** (cholestyramine, colestipol, colesevelam) effectively lower **LDL cholesterol by 15-25%** by sequestering bile acids in the intestine, leading to increased hepatic LDL receptor expression [1].- They produce a modest but beneficial **3-5% increase in HDL cholesterol**.- This represents the typical therapeutic effect at standard doses.*Incorrect: 3-5% decrease in LDL-C and 1-3% increase in HDL-C*- This represents a **much smaller effect** on both LDL-C and HDL-C than typically observed with therapeutic doses of bile acid resins.- Such marginal LDL-C reduction (3-5%) would be **clinically insignificant** for most dyslipidemic patients requiring treatment.*Incorrect: 25-35% decrease in LDL-C and 1-3% increase in HDL-C*- While bile acid resins can achieve significant **LDL-C reduction**, the 25-35% range is on the **higher end** of what's typically seen (more common with maximum doses or combination therapy).- The **HDL-C increase of 1-3%** is lower than the standard 3-5% increase commonly reported for this drug class.*Incorrect: 5-10% decrease in LDL-C and 1-3% increase in HDL-C*- This magnitude of **LDL-C reduction is suboptimal** for patients requiring lipid-lowering therapy with bile acid resins.- Both the LDL-C decrease and HDL-C increase are below the expected therapeutic range for this medication class.

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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