Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 611: What is the drug of choice in patients with Wolff-Parkinson-White syndrome with atrial fibrillation?

A. Digitalis
B. Procainamide (Correct Answer)
C. Verapamil
D. Adenosine

Explanation: In **Wolff-Parkinson-White (WPW) syndrome**, an accessory pathway (Bundle of Kent) bypasses the AV node [3]. When atrial fibrillation (AF) occurs in these patients, impulses can conduct rapidly down the accessory pathway, which has a shorter refractory period than the AV node. This can lead to extremely high ventricular rates, potentially degenerating into ventricular fibrillation (VF) [1]. **Why Procainamide is the Correct Choice:** Procainamide is a **Class IA antiarrhythmic** that increases the refractory period of both the atrium and the **accessory pathway** [2]. By slowing conduction through the bypass tract, it effectively reduces the ventricular rate and may even terminate the arrhythmia. In hemodynamically stable patients with WPW and AF, Procainamide is the drug of choice. **Why Other Options are Incorrect:** * **Digitalis (Digoxin), Verapamil, and Adenosine:** These drugs are **AV node blockers**. By blocking the AV node, they paradoxically favor conduction through the accessory pathway. This "redirects" all atrial impulses to the bypass tract, which can lead to a rapid increase in ventricular rate and precipitate **Ventricular Fibrillation** [1]. They are strictly contraindicated in WPW with AF. **High-Yield Clinical Pearls for NEET-PG:** * **Hemodynamically Unstable Patients:** If a patient with WPW and AF is unstable (hypotension, altered mentation), the immediate treatment is **DC Cardioversion**. * **Definitive Treatment:** The gold standard for long-term management of WPW syndrome is **Radiofrequency Catheter Ablation** of the accessory pathway. * **Avoid "ABCD":** Remember the mnemonic to avoid **A**denosine, **B**eta-blockers, **C**alcium channel blockers, and **D**igoxin in WPW with AF.

Question 612: Which drug commonly causes hirsutism and gynecomastia?

A. Spironolactone (Correct Answer)
B. Rifampicin
C. Penicillin
D. Bumetanide

Explanation: **Explanation:** **Spironolactone** is a potassium-sparing diuretic that acts as a competitive antagonist at the mineralocorticoid (aldosterone) receptor. Its side effect profile is a high-yield topic for NEET-PG due to its non-specific binding to other steroid receptors. 1. **Why Spironolactone is correct:** * **Gynecomastia:** Spironolactone has anti-androgenic effects. It inhibits the binding of dihydrotestosterone (DHT) to androgen receptors and increases the peripheral conversion of testosterone to estradiol. This hormonal imbalance leads to painful gynecomastia in males. * **Hirsutism:** Interestingly, while it causes feminizing effects in men, it is used clinically to *treat* hirsutism in women (e.g., in PCOS) by blocking androgen receptors in hair follicles. However, in the context of general drug side effects, it is classically associated with endocrine disturbances including menstrual irregularities and breast tenderness. 2. **Why other options are incorrect:** * **Rifampicin:** An antitubercular drug known for causing orange-colored secretions (urine, sweat, tears) and being a potent hepatic enzyme inducer. * **Penicillin:** Primarily associated with hypersensitivity reactions (Type I IgE-mediated) and interstitial nephritis. * **Bumetanide:** A potent loop diuretic. Like Furosemide, its main side effects are ototoxicity, hypokalemia, and hyperuricemia, but it does not have anti-androgenic properties. **Clinical Pearls for NEET-PG:** * **Eplerenone** is a selective aldosterone antagonist that does **not** cause gynecomastia, making it the preferred alternative if these side effects occur. * Other common drugs causing gynecomastia (Mnemonic: **DISCO**): **D**igoxin, **I**soniazid, **S**pironolactone, **C**imetidine, **O**estrogens/Ketoconazole. * Spironolactone is the drug of choice for **Conn’s Syndrome** (Primary Hyperaldosteronism) and ascites in **Liver Cirrhosis**.

Question 613: Which of the following statements about digoxin is false?

A. Dosage reduction is required in hepatic disease. (Correct Answer)
B. Dosage reduction is required in renal failure.
C. It can cause bradycardia.
D. It increases the force of contraction in congestive heart failure.

Explanation: **Explanation:** The correct answer is **A**, as digoxin is primarily eliminated by the kidneys, not the liver. **1. Why Option A is False (The Correct Answer):** Digoxin is a polar glycoside with a unique pharmacokinetic profile. Approximately **60-80% of the drug is excreted unchanged in the urine** via glomerular filtration and P-glycoprotein secretion. Since it does not undergo significant hepatic metabolism, its clearance is independent of liver function. Therefore, dosage reduction is **not** required in hepatic disease. **2. Why the other options are True:** * **Option B:** Because digoxin is primarily renally excreted, its half-life (normally 36–40 hours) increases significantly in **renal failure**, leading to toxicity. Dose adjustment based on creatinine clearance is mandatory. * **Option C:** Digoxin has **parasympathomimetic (vagotonic) effects**, which slow the conduction through the AV node and decrease the heart rate. This makes it useful in controlling ventricular rate in atrial fibrillation but can cause symptomatic bradycardia. * **Option D:** Digoxin is a **positive inotrope**. It inhibits the Na+/K+-ATPase pump, leading to an increase in intracellular sodium, which subsequently increases intracellular calcium via the Na+/Ca2+ exchanger. This enhances the force of myocardial contraction. **High-Yield Clinical Pearls for NEET-PG:** * **Antidote:** Digoxin Immune Fab (Digibind). * **Electrolyte Interactions:** **Hypokalemia**, hypomagnesemia, and hypercalcemia predispose to digoxin toxicity. * **ECG Changes:** The earliest sign of toxicity is often PVCs; the most characteristic sign is the "Reverse Tick" or "Sagging" ST-segment depression. * **Drug Interactions:** Quinidine, Verapamil, and Amiodarone increase digoxin levels by displacing it from tissue binding sites and reducing renal clearance.

Question 614: Nicotinic acid is useful in all types of hyperlipoproteinemias, EXCEPT:

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

Explanation: **Explanation:** Nicotinic acid (Niacin) is a broad-spectrum hypolipidemic agent that acts by inhibiting **hormone-sensitive lipase** in adipose tissue. This reduces the breakdown of triglycerides into free fatty acids (FFAs). Since FFAs are the primary substrate for hepatic VLDL synthesis, Niacin effectively lowers VLDL, and subsequently its metabolite, LDL. **Why Type-I is the Correct Answer:** * **Type-I Hyperlipoproteinemia (Familial Chylomicronemia)** is characterized by a deficiency in **Lipoprotein Lipase (LPL)** or its cofactor, ApoC-II. This leads to a massive accumulation of **Chylomicrons** in the plasma. * Niacin does not significantly affect the clearance of dietary chylomicrons; its primary mechanism is reducing endogenous VLDL production. Therefore, it is ineffective in treating Type-I. **Why the other options are incorrect:** * **Type-II (Familial Hypercholesterolemia):** Niacin reduces LDL levels by decreasing VLDL synthesis and inhibiting hepatic diacylglycerol acyltransferase-2. It is a potent agent for lowering LDL (Type-IIa) and VLDL (Type-IIb). * **Type-III (Dysbetalipoproteinemia):** Niacin helps reduce IDL (Remnant particles) by decreasing the precursor VLDL. * **Type-IV (Familial Hypertriglyceridemia):** Niacin is highly effective here as it directly inhibits VLDL secretion, which is the hallmark of Type-IV. **High-Yield Clinical Pearls for NEET-PG:** * **Most Potent Effect:** Niacin is the most effective drug for **increasing HDL levels** (by decreasing HDL catabolism). * **Lp(a) Reduction:** It is one of the few drugs that significantly lowers **Lipoprotein(a)**. * **Side Effects:** The most common side effect is **cutaneous flushing** (mediated by Prostaglandin $D_2$ and $E_2$), which can be prevented by taking **Aspirin** 30 minutes prior. * **Metabolic Risks:** It can cause **hyperuricemia** (precipitating gout) and **hyperglycemia** (acanthosis nigricans is a rare sign of insulin resistance here).

Question 615: Digoxin toxicity is aggravated by which of the following electrolyte imbalances?

A. Hyperkalemia (Correct Answer)
B. Hypokalemia
C. Hypermagnesemia
D. Hypocalcemia

Explanation: **Explanation:** The correct answer is **A. Hyperkalemia**. **Mechanism of Action & Toxicity:** Digoxin works by inhibiting the **Na⁺/K⁺-ATPase pump** on the cardiac myocyte membrane. Under normal physiological conditions, potassium (K⁺) competes with digoxin for the same binding site on this pump. * **In Hypokalemia:** There is less competition for the binding site, allowing more digoxin to bind, which **precipitates** or worsens toxicity even at normal serum levels. * **In Hyperkalemia:** High extracellular potassium levels compete with and displace digoxin from the pump. Therefore, hyperkalemia **antagonizes** the effects of digoxin and is a common **consequence** of acute digoxin poisoning (as the pumps are blocked, K⁺ cannot enter the cell), but it does not aggravate the toxicity; rather, it reduces digoxin's binding affinity. **Analysis of Options:** * **B. Hypokalemia:** This is the most common electrolyte abnormality that **precipitates** digoxin toxicity. Low K⁺ increases digoxin binding to the Na⁺/K⁺-ATPase. * **C. Hypermagnesemia:** Actually, **Hypomagnesemia** predisposes to toxicity. Magnesium is a cofactor for the Na⁺/K⁺-ATPase pump; its deficiency impairs the pump further. * **D. Hypocalcemia:** Digoxin increases intracellular calcium to exert its positive inotropic effect. Therefore, **Hypercalcemia** (not hypocalcemia) aggravates toxicity and can lead to dangerous arrhythmias like "Stone Heart." **High-Yield Clinical Pearls for NEET-PG:** 1. **Electrolytes that worsen Digoxin Toxicity:** Hypokalemia, Hypomagnesemia, and Hypercalcemia. 2. **ECG Hallmark:** The most common arrhythmia is PVCs; the most characteristic is **Atrial Tachycardia with AV block**. 3. **Visual Side Effect:** Xanthopsia (yellow-green halos around lights). 4. **Antidote:** Digoxin-specific antibody fragments (**DigiFab**). 5. **Management of Hyperkalemia in Toxicity:** Avoid Calcium Gluconate (may cause "Stone Heart"); use DigiFab and insulin/glucose instead.

Question 616: Which of the following antihypertensive drugs does not alter serum glucose and lipid levels?

A. Propranolol
B. Prazosin (Correct Answer)
C. Thiazide diuretics
D. None of the above

Explanation: **Explanation:** The metabolic profile of antihypertensive drugs is a high-yield topic for NEET-PG. The correct answer is **Prazosin**, a selective alpha-1 (α₁) blocker. **1. Why Prazosin is correct:** Alpha-1 blockers like Prazosin, Terazosin, and Doxazosin are considered **metabolically neutral** or even beneficial. They do not impair glucose tolerance or increase insulin resistance. Clinically, they may slightly improve lipid profiles by decreasing LDL and triglycerides while increasing HDL. This makes them a suitable choice for hypertensive patients with comorbid diabetes or dyslipidemia. **2. Why the other options are incorrect:** * **Propranolol (Non-selective Beta-blocker):** These drugs typically worsen the metabolic profile. They inhibit insulin release (via β₂ blockade in the pancreas), mask hypoglycemic symptoms (except sweating), and increase triglycerides while decreasing HDL. * **Thiazide Diuretics:** These are notorious for causing **hyperglycemia** (by inhibiting insulin release and causing hypokalemia) and **hyperlipidemia** (increasing LDL and cholesterol levels). They also cause hyperuricemia and hypercalcemia. **Clinical Pearls for NEET-PG:** * **ACE Inhibitors and ARBs:** These are the drugs of choice for diabetics as they improve insulin sensitivity and provide renoprotection. * **Calcium Channel Blockers (CCBs):** Like Prazosin, CCBs are also metabolically neutral. * **Prazosin Side Effect:** Always remember the **"First Dose Phenomenon"** (severe orthostatic hypotension), which is why it is usually administered at bedtime. * **BPH:** Alpha-blockers are the preferred antihypertensives in patients with Benign Prostatic Hyperplasia as they relax the bladder neck.

Question 617: Which beta-blocker possesses intrinsic sympathomimetic activity?

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

Explanation: ### Explanation **1. Understanding the Concept: Intrinsic Sympathomimetic Activity (ISA)** Beta-blockers with ISA (also known as **partial agonists**) do not completely block the beta-receptor. Instead, they cause low-level activation of the receptor while preventing stronger endogenous catecholamines (like epinephrine) from binding. This results in a smaller decrease in resting heart rate and cardiac output compared to pure antagonists. **2. Why Acebutolol is Correct** **Acebutolol** (along with Pindolol) is a classic example of a beta-blocker with ISA. Because it partially stimulates beta-receptors, it is particularly useful in patients who require beta-blockade but suffer from excessive bradycardia or have a limited cardiac reserve. **3. Analysis of Incorrect Options** * **A. Propranolol:** A prototype non-selective beta-blocker (blocks $\beta_1$ and $\beta_2$). It is a pure antagonist and lacks ISA. * **B. Carvedilol:** A non-selective beta-blocker that also possesses **$\alpha_1$-blocking activity**, leading to peripheral vasodilation. It does not have ISA. * **D. Atenolol:** A cardioselective ($\beta_1$) blocker. It is a pure antagonist and is commonly used for hypertension and angina, but it lacks ISA. **4. High-Yield Clinical Pearls for NEET-PG** * **Mnemonic for ISA:** "**P**apa **A**nd **C**hild **L**ove **M**ilk" (**P**indolol, **A**cebutolol, **C**eliprolol, **L**abetalol, **M**etoprolol—*note: Metoprolol has very weak/negligible ISA, but Pindolol and Acebutolol are the primary exam answers*). * **Clinical Advantage:** Beta-blockers with ISA are less likely to cause severe bradycardia or cold extremities (Raynaud's phenomenon) because they maintain a basal level of sympathetic tone. * **Contraindication:** They are generally **avoided** in the immediate post-MI period because they do not reduce the cardiac workload as effectively as pure antagonists like Metoprolol or Bisoprolol.

Question 618: Which antihypertensive is a prodrug and is converted to its active form in the brain?

A. Clonidine
B. Methyldopa (Correct Answer)
C. Minoxidil
D. Nitroprusside

Explanation: **Explanation:** **Methyldopa** is the correct answer because it is a centrally acting antihypertensive that functions as a **prodrug**. After crossing the blood-brain barrier, it is taken up by noradrenergic neurons and converted via the catecholamine synthesis pathway: * Methyldopa → α-methyldopamine → **α-methylnorepinephrine** (the active metabolite). This active form stimulates central **α₂-adrenergic receptors** in the nucleus tractus solitarius, leading to a decrease in sympathetic outflow and a subsequent fall in blood pressure. **Analysis of Incorrect Options:** * **Clonidine:** While also a central α₂-agonist, it is **not a prodrug**. It is active in its original form and directly stimulates the receptors. * **Minoxidil:** This is a potent vasodilator (K⁺ channel opener). While it is a prodrug, it is converted to its active form (minoxidil sulfate) in the **liver**, not the brain. * **Nitroprusside:** This is a direct-acting vasodilator that releases nitric oxide (NO) spontaneously in the blood; it does not require metabolic activation in the brain. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** Methyldopa remains a preferred antihypertensive in **pregnancy** (Gestational Hypertension/Preeclampsia). * **Adverse Effects:** Can cause a **positive Direct Coombs Test** (hemolytic anemia), sedation, and drug-induced lupus-like syndrome. * **Mechanism Tip:** Remember "False Neurotransmitter" – α-methylnorepinephrine replaces NE in vesicles but acts as a potent agonist only at inhibitory α₂ receptors.

Question 619: Which of the following drugs, when combined with erythromycin, may cause ventricular arrhythmias?

A. Tetracycline
B. Streptomycin
C. Ebastine
D. Cisapride (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Cisapride** **Mechanism of Interaction:** The combination of **Erythromycin** (a Macrolide antibiotic) and **Cisapride** (a prokinetic agent) is a classic example of a dangerous drug-drug interaction. 1. **Pharmacokinetic Interaction:** Erythromycin is a potent inhibitor of the hepatic enzyme **CYP3A4** [3]. Cisapride is primarily metabolized by this same enzyme [2]. Inhibition leads to toxic levels of Cisapride in the plasma. 2. **Pharmacodynamic Interaction:** High levels of Cisapride block the delayed rectifier potassium channels ($I_{Kr}$) in the heart, leading to **QT interval prolongation** [1]. This predisposes the patient to a life-threatening polymorphic ventricular tachycardia known as **Torsades de Pointes (TdP)** [1]. **Analysis of Incorrect Options:** * **A. Tetracycline:** These act on the 30S ribosomal subunit. They do not significantly inhibit CYP3A4 or prolong the QT interval; thus, they do not carry a high risk of arrhythmia when combined with erythromycin. * **B. Streptomycin:** An aminoglycoside that primarily causes ototoxicity and nephrotoxicity. It does not interact with the CYP system or cardiac ion channels to cause arrhythmias. * **C. Ebastine:** While some second-generation antihistamines (like Terfenadine and Astemizole) were withdrawn for causing TdP when combined with CYP3A4 inhibitors, Ebastine has a much higher safety margin and is not the primary "textbook" answer for this interaction compared to Cisapride. **High-Yield Clinical Pearls for NEET-PG:** * **The "QT-Prolonging" List:** Other drugs to watch for include Class IA and III antiarrhythmics, Haloperidol, and Fluoroquinolones. * **Macrolide Safety:** Among macrolides, **Azithromycin** has the least inhibitory effect on CYP3A4, making it safer regarding metabolic drug interactions than Erythromycin or Clarithromycin. * **Cisapride Status:** Due to the risk of sudden cardiac death, Cisapride has been restricted or withdrawn in many markets [1].

Question 620: What is the antihypertensive drug of choice for elderly patients with hypertension?

A. ACE inhibitor or Diuretics
B. ACE inhibitor or Beta blocker
C. ACE inhibitor or Calcium channel blocker
D. Calcium channel blocker or Diuretics (Correct Answer)

Explanation: In elderly patients, hypertension is often characterized by **Isolated Systolic Hypertension (ISH)**. This occurs due to age-related arterial stiffening and reduced vascular compliance [1]. Pathophysiologically, the elderly tend to have **low-renin hypertension** and are more sensitive to salt intake. **Why Option D is Correct:** * **Calcium Channel Blockers (CCBs):** Long-acting dihydropyridines (e.g., Amlodipine) are highly effective in the elderly because they directly reduce peripheral vascular resistance, addressing the arterial stiffness characteristic of this age group [2]. * **Thiazide Diuretics:** These are particularly effective in low-renin, salt-sensitive hypertension [4]. Large-scale trials (like ALLHAT and SHEP) have consistently shown that diuretics and CCBs significantly reduce the risk of stroke and cardiovascular events in the elderly. **Why Other Options are Incorrect:** * **ACE Inhibitors (Options A, B, C):** While excellent for patients with diabetes or heart failure, ACEIs are generally less effective as monotherapy in the elderly due to the naturally low plasma renin levels found in this population. * **Beta-Blockers (Option B):** These are no longer considered first-line for uncomplicated hypertension in the elderly [3]. They are less effective at preventing strokes and can increase the risk of new-onset diabetes and bradycardia in older patients. **High-Yield NEET-PG Pearls:** * **JNC-8 Guidelines:** Recommend Thiazides or CCBs as first-line for the general non-black population (including elderly); however, for the **Black population**, Thiazides or CCBs are strictly preferred over ACEIs. * **Drug of Choice for ISH:** Long-acting Dihydropyridine CCBs [2]. * **Side Effect Note:** When using diuretics in the elderly, monitor for hyponatremia and hypokalemia, as they are more susceptible to electrolyte imbalances.

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

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free