Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 281: Propranolol should not be given to a patient on treatment with which of the following drugs?

A. Nifedipine
B. Nitrates
C. Verapamil (Correct Answer)
D. ACE inhibitor

Explanation: **Explanation:** The correct answer is **Verapamil**. **1. Why Verapamil is the correct answer:** Both Propranolol (a non-selective beta-blocker) and Verapamil (a non-dihydropyridine calcium channel blocker) exert potent **negative inotropic** (decreased contractility) and **negative chronotropic/dromotropic** (decreased heart rate and AV conduction) effects. When administered together, they have a synergistic inhibitory effect on the SA and AV nodes. This significantly increases the risk of severe **bradycardia, AV block, and acute heart failure**. Therefore, this combination is generally contraindicated. **2. Why other options are incorrect:** * **Nifedipine:** This is a dihydropyridine CCB that primarily causes vasodilation. It often triggers reflex tachycardia. Beta-blockers like Propranolol are actually frequently combined with Nifedipine to counteract this reflex tachycardia. * **Nitrates:** These are commonly used with beta-blockers in stable angina. Nitrates cause venodilation and reflex tachycardia, which Propranolol prevents, while Propranolol prevents the increase in end-diastolic volume caused by nitrates. This is a beneficial synergy. * **ACE Inhibitors:** There is no direct contraindication. In fact, the combination of a beta-blocker and an ACE inhibitor is a cornerstone in the management of Chronic Heart Failure (CHF) and post-myocardial infarction. **High-Yield Clinical Pearls for NEET-PG:** * **Diltiazem**, like Verapamil, should also be used with extreme caution with beta-blockers due to similar risks of AV block. * **Beta-blocker overdose antidote:** Glucagon (increases cAMP bypassing the beta-receptor). * **Verapamil specific side effect:** Constipation (most common) and hyperprolactinemia. * **Drug of choice for SVT:** Adenosine (Verapamil is an alternative).

Question 282: A 33-year-old patient with a history of asthma is being treated for symptoms of hypertension. Which of the following beta-blockers would be an appropriate therapy for this patient?

A. Isoprenaline
B. Labetalol
C. Metoprolol (Correct Answer)
D. Propranolol

Explanation: ### Explanation **Correct Answer: C. Metoprolol** **Concept: Cardioselectivity in Beta-Blockers** The primary concern when treating a hypertensive patient with co-existing asthma is avoiding bronchospasm. Bronchospasm is triggered by the blockade of **$eta_2$ receptors** located in the bronchial smooth muscle [1]. Therefore, in asthmatic patients, **Cardioselective ($eta_1$-selective) beta-blockers** are preferred because they primarily inhibit $eta_1$ receptors in the heart while sparing $eta_2$ receptors in the lungs (at therapeutic doses) [1]. **Metoprolol** is a second-generation, cardioselective $eta_1$ blocker, making it a safer choice for patients with reactive airway diseases compared to non-selective agents [1]. --- ### Analysis of Incorrect Options: * **A. Isoprenaline:** This is a potent **non-selective $eta$-agonist** (stimulates both $eta_1$ and $eta_2$). It would increase heart rate and blood pressure, making it contraindicated for hypertension. * **B. Labetalol:** This is a **non-selective $eta$-blocker** with additional $\alpha_1$-blocking activity. Because it blocks $eta_2$ receptors, it can precipitate a severe asthma attack [1]. * **D. Propranolol:** This is the prototype **non-selective $eta$-blocker**. It blocks both $eta_1$ and $eta_2$ receptors and is strictly contraindicated in patients with asthma or COPD [1]. --- ### NEET-PG High-Yield Pearls: * **Mnemonic for Cardioselective ($eta_1$) Blockers:** "**A** New **B**eta **B**locker **E**xcites **M**odern **C**ardiologists" (**A**tenolol, **N**ebivolol, **B**isoprolol, **B**etaxolol, **E**smolol, **M**etoprolol, **C**eliprolol). * **Esmolol** has the shortest half-life (~9 minutes) and is used for hypertensive emergencies. * **Nebivolol** is the most highly selective $eta_1$ blocker and also produces vasodilation via Nitric Oxide (NO) release. * **Important Caveat:** "Cardioselectivity" is dose-dependent; at high doses, even metoprolol can lose its selectivity and cause bronchoconstriction.

Question 283: Which of the following potassium-sparing diuretics reduces cardiac mortality?

A. Spironolactone (Correct Answer)
B. Amiloride
C. Triamterene
D. All the above

Explanation: The correct answer is **Spironolactone**. **1. Why Spironolactone is correct:** Spironolactone is a **Mineralocorticoid Receptor Antagonist (MRA)** [3]. In patients with heart failure, high levels of aldosterone lead to pathological cardiac remodeling, myocardial fibrosis, and collagen deposition. Spironolactone blocks these effects, thereby preventing structural damage to the heart. The landmark **RALES trial** demonstrated that adding spironolactone to standard therapy significantly reduces morbidity and mortality in patients with Heart Failure with reduced Ejection Fraction (HFrEF). Eplerenone, another MRA, shows similar mortality benefits (EMPHASIS-HF trial). Eplerenone is more selective and does not typically cause gynecomastia [1]. **2. Why the other options are incorrect:** * **Amiloride and Triamterene:** These are **epithelial sodium channel (ENaC) blockers** that act directly on the distal tubule [1]. While they are potassium-sparing diuretics, they do not antagonize the aldosterone receptor. Consequently, they do not prevent cardiac fibrosis or remodeling and have **no proven mortality benefit** in heart failure. They are primarily used to counteract potassium loss caused by thiazides or loop diuretics. **3. High-Yield NEET-PG Pearls:** * **Mechanism:** Spironolactone is a competitive antagonist of aldosterone at the late distal tubule and collecting duct [2, 3]. * **Side Effects:** The most characteristic side effect is **gynecomastia** and impotence in men (due to non-specific binding to androgen and progesterone receptors) [1]. Eplerenone is more selective and does not typically cause gynecomastia. * **Contraindication:** Avoid in patients with significant renal impairment or **hyperkalemia** (K+ > 5.0 mEq/L) [2, 3]. * **Drug of Choice:** Spironolactone is the drug of choice for **primary hyperaldosteronism (Conn’s Syndrome)** and edema associated with **liver cirrhosis**.

Question 284: Which drug class is contraindicated in pregnancy?

A. Angiotensin receptor blockers (Correct Answer)
B. Beta blockers
C. Calcium channel blockers
D. Thiazides

Explanation: **Explanation:** **Angiotensin Receptor Blockers (ARBs)**, along with ACE inhibitors and Direct Renin Inhibitors, are strictly **contraindicated in pregnancy (Category D)**. The underlying medical concept is their interference with the fetal Renin-Angiotensin-Aldosterone System (RAAS), which is essential for normal fetal renal development. Exposure, particularly during the second and third trimesters, leads to **fetal renal dysgenesis**, resulting in oligohydramnios. This lack of amniotic fluid causes the **"Potter Sequence"** (pulmonary hypoplasia, cranial malformations, and limb deformities). **Analysis of Incorrect Options:** * **Beta-blockers (B):** Generally considered safe, though they may be associated with fetal bradycardia or Intrauterine Growth Restriction (IUGR). Labetalol is a first-line agent for pregnancy-induced hypertension. * **Calcium Channel Blockers (C):** Nifedipine (long-acting) is frequently used and considered safe for managing hypertension in pregnancy. * **Thiazides (D):** Not typically started *de novo* during pregnancy due to the risk of volume depletion and electrolyte imbalances, but they are not absolute contraindications if the patient was already well-controlled on them prior to conception. **High-Yield Clinical Pearls for NEET-PG:** * **Safe Antihypertensives in Pregnancy:** Remember the mnemonic **"Better Mother Care During Hypertensive"** (Beta-blockers/Labetalol, Methyldopa, CCBs/Nifedipine, Hydralazine). * **Drug of Choice:** **Labetalol** is currently the preferred drug for chronic hypertension in pregnancy; **Methyldopa** is the classic historical answer. * **Hydralazine** is used primarily for hypertensive emergencies in pregnancy (Preeclampsia/Eclampsia). * **Teratogenic effect of ACEi/ARBs:** Hypocalvaria (incomplete ossification of skull bones) is a specific board-favorite association.

Question 285: Which of the following drugs has a favorable effect on lipid metabolism?

A. Atenolol
B. Chlorothiazide
C. Clonidine (Correct Answer)
D. Torsemide

Explanation: **Explanation:** The metabolic impact of antihypertensive drugs is a high-yield topic for NEET-PG. The correct answer is **Clonidine**. **1. Why Clonidine is correct:** Clonidine is a centrally acting $\alpha_2$-agonist. Unlike many other antihypertensives, it has a **favorable or neutral effect** on lipid metabolism. It has been shown to slightly decrease total cholesterol, LDL (low-density lipoprotein), and triglycerides while potentially increasing HDL (high-density lipoprotein). Its mechanism involves reducing sympathetic outflow, which prevents the catecholamine-mediated stimulation of lipolysis, thereby improving the lipid profile. **2. Why the other options are incorrect:** * **Atenolol (Beta-blockers):** Non-selective and older cardioselective $\beta$-blockers (like Atenolol) typically have an **unfavorable** effect. They decrease HDL and increase triglycerides by inhibiting lipoprotein lipase (LPL) activity. (Note: Newer vasodilatory $\beta$-blockers like Carvedilol/Nebivolol are lipid-neutral). * **Chlorothiazide (Thiazide Diuretics):** These are notorious for causing **dyslipidemia**. They typically increase total cholesterol, LDL, and triglycerides, especially at higher doses, by interfering with insulin sensitivity. * **Torsemide (Loop Diuretics):** Similar to thiazides, loop diuretics can cause transient increases in plasma lipids and glucose levels, making them metabolically unfavorable compared to centrally acting agents or ACE inhibitors. **Clinical Pearls for NEET-PG:** * **Lipid-Friendly Drugs:** Alpha-blockers (Prazosin), ACE inhibitors, ARBs, and Calcium Channel Blockers (CCBs) are generally considered lipid-neutral or favorable. * **Alpha-1 Blockers (Prazosin):** These are the most "lipid-favorable" antihypertensives as they significantly increase HDL/LDL ratio. * **Diuretics and Beta-blockers:** Both can worsen insulin resistance and the lipid profile; they should be used cautiously in patients with Metabolic Syndrome.

Question 286: Which of the following is NOT a known side effect or characteristic of beta-blockers?

A. Postural hypotension (Correct Answer)
B. Bradycardia
C. Glucagon used for toxicity
D. Lipid soluble drugs cause bad dreams

Explanation: **Explanation:** **1. Why Postural Hypotension is the Correct Answer:** Postural (orthostatic) hypotension is primarily caused by the blockade of **alpha-1 adrenergic receptors**, which prevents compensatory vasoconstriction when standing. Pure beta-blockers (like Propranolol or Atenolol) do not cause postural hypotension because they do not affect alpha receptors; instead, they may cause a modest decrease in blood pressure through reduced cardiac output and renin inhibition. *Note:* Mixed alpha/beta-blockers like **Labetalol** or **Carvedilol** can cause postural hypotension, but it is not a characteristic of the beta-blocker class as a whole. **2. Analysis of Incorrect Options:** * **B. Bradycardia:** This is a classic pharmacological effect. Beta-1 blockade at the SA node decreases heart rate (negative chronotropy). * **C. Glucagon for toxicity:** Glucagon is the **antidote of choice** for beta-blocker overdose. It bypasses the blocked beta-receptors to increase intracellular cAMP via glucagon receptors, restoring heart rate and contractility. * **D. Lipid solubility and bad dreams:** Lipophilic beta-blockers (e.g., **Propranolol**, Metoprolol) easily cross the blood-brain barrier. This leads to CNS side effects such as vivid dreams, nightmares, and depression. **3. NEET-PG High-Yield Pearls:** * **Water-soluble (Renal excretion):** Atenolol, Sotalol, Nadolol (Mnemonic: **A**ll **S**afe **N**ow). * **Lipid-soluble (Hepatic metabolism):** Propranolol, Metoprolol. * **Contraindications:** Always avoid beta-blockers in patients with **Prinzmetal angina** (causes unopposed alpha-vasoconstriction) and **Asthma/COPD** (due to bronchospasm from Beta-2 blockade). * **Diabetes:** They can mask the tachycardic warning signs of hypoglycemia.

Question 287: What is the best treatment for severe digitalis toxicity?

A. Potassium supplements
B. Diphenylhydantoin
C. Quinidine
D. Fab fragments of digitalis antibodies (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Fab fragments of digitalis antibodies (Digibind)** **Why it is correct:** In cases of **severe digitalis toxicity** (characterized by life-threatening arrhythmias, hyperkalemia >5.5 mEq/L, or massive ingestion), **Digoxin-specific antibody fragments (Fab)** are the definitive treatment of choice. These fragments bind to free digoxin in the extracellular space, creating a complex that is rapidly excreted by the kidneys. This effectively lowers the free drug concentration and reverses the inhibition of the Na+/K+-ATPase pump. **Why the other options are incorrect:** * **A. Potassium supplements:** While hypokalemia predisposes to digitalis toxicity, severe toxicity itself often causes **hyperkalemia** (due to pump inhibition). Giving potassium in severe cases can be fatal. It is only used in mild toxicity with documented hypokalemia. * **B. Diphenylhydantoin (Phenytoin):** This was historically used to treat digitalis-induced ventricular arrhythmias because it suppresses abnormal automaticity without worsening AV block. However, it is not the "best" or definitive treatment for severe systemic toxicity. * **C. Quinidine:** This is **contraindicated**. Quinidine reduces the renal clearance of digoxin and displaces it from tissue binding sites, doubling the plasma concentration of digoxin and worsening toxicity. **High-Yield Clinical Pearls for NEET-PG:** * **Most common ECG finding:** Ventricular Bigeminy. * **Most characteristic ECG finding:** Bidirectional Ventricular Tachycardia. * **Earliest symptom:** Anorexia, nausea, and vomiting. * **Visual disturbance:** Xanthopsia (yellow-green vision). * **Electrolyte trigger:** Hypokalemia, hypomagnesemia, and hypercalcemia increase the risk of toxicity. * **Management of choice for Digoxin-induced Bradycardia:** Atropine.

Question 288: All of the following are selective beta-1 blockers except?

A. Atenolol
B. Esmolol
C. Bisoprolol
D. Sotalol (Correct Answer)

Explanation: The classification of beta-blockers is a high-yield topic for NEET-PG. Beta-blockers are divided into non-selective (Block eta_1 and eta_2) and cardioselective (Block primarily eta_1) [1]. **Why Sotalol is the correct answer:** **Sotalol** is a **non-selective beta-blocker** (Second generation) [1]. Uniquely, it also possesses **Class III antiarrhythmic properties** (potassium channel blockade), which prolongs the action potential duration and the QT interval. Because it blocks both eta_1 and eta_2 receptors, it is not considered cardioselective. **Analysis of incorrect options (Selective eta_1 blockers):** * **Atenolol:** A classic second-generation cardioselective blocker. It is hydrophilic and has a low risk of CNS side effects. * **Esmolol:** An ultra-short-acting cardioselective blocker (half-life ~9 minutes) administered IV, primarily used for intraoperative tachycardia or hypertensive emergencies [2]. * **Bisoprolol:** A highly selective eta_1 blocker commonly used in the management of chronic heart failure and hypertension [1]. **NEET-PG Clinical Pearls:** * **Mnemonic for Cardioselective (eta_1) blockers:** *"New Beta Blockers Are Exclusive to My Heart"* (**N**ebivolol, **B**etaxolol, **B**isoprolol, **A**tenolol, **E**smolol, **M**etoprolol, **H**acebutolol) [1, 2]. * **Sotalol Caution:** Due to its Class III effect, it can cause **Torsades de Pointes** (prolonged QT interval). * **Non-selective blockers with alpha-blocking activity:** Carvedilol and Labetalol (Third generation). * **Drug of choice for Esmolol:** Aortic dissection (acute management) and supraventricular arrhythmias during surgery.

Question 289: Propranolol is not used in which of the following conditions?

A. AV block (Correct Answer)
B. Hypertension
C. Hypertrophic obstructive cardiomyopathy
D. Migraine

Explanation: **Explanation:** The correct answer is **AV block**. Propranolol is a non-selective beta-adrenergic antagonist that exerts significant effects on the cardiac conduction system. **1. Why AV Block is the Correct Answer:** Propranolol blocks $\beta_1$ receptors in the heart, leading to **negative dromotropy** (decreased conduction velocity) and **negative chronotropy** (decreased heart rate). Specifically, it increases the refractory period of the Atrioventricular (AV) node. In patients with pre-existing AV block, propranolol can further delay conduction, potentially progressing to a complete heart block or cardiac arrest. Therefore, it is strictly contraindicated. **2. Why Other Options are Incorrect:** * **Hypertension:** Beta-blockers reduce blood pressure by decreasing cardiac output and inhibiting renin release from the juxtaglomerular apparatus. While no longer first-line for uncomplicated hypertension, they remain a valid treatment option. * **Hypertrophic Obstructive Cardiomyopathy (HOCM):** Propranolol is a drug of choice here. By decreasing the force of contraction (negative inotropy) and heart rate, it reduces the outflow tract obstruction and improves diastolic filling. * **Migraine:** Propranolol is the standard drug for the **prophylaxis** of migraine (not acute attacks) due to its ability to modulate cerebral blood flow and prevent vasodilation. **Clinical Pearls for NEET-PG:** * **Contraindications of Beta-blockers:** Remember the mnemonic **ABCDE** — **A**sthma/COPD (due to $\beta_2$ blockade causing bronchospasm), **B**lock (Heart block), **C**ongestive Heart Failure (acute/decompensated), **D**iabetes mellitus (masks hypoglycemic tachycardia), and **E**xtremities (Peripheral vascular disease/Raynaud's). * **Lipid Solubility:** Propranolol is highly lipid-soluble, allowing it to cross the blood-brain barrier, which explains its efficacy in migraine and its side effect of vivid dreams/nightmares.

Question 290: What is the most potent cardiac stimulant among the following?

A. Adrenaline (Correct Answer)
B. Noradrenaline
C. Ephedrine
D. Salbutamol

Explanation: **Explanation:** **Adrenaline (Epinephrine)** is the most potent cardiac stimulant because it is a potent agonist at **$\beta_1$, $\beta_2$, and $\alpha$ receptors**. Its action on $\beta_1$ receptors in the myocardium leads to a powerful increase in heart rate (positive chronotropy), force of contraction (positive inotropy), and conduction velocity (positive dromotropy). Unlike other catecholamines, it significantly increases cardiac output while simultaneously maintaining or increasing coronary perfusion. **Analysis of Options:** * **Noradrenaline:** While it has strong $\beta_1$ activity, its potent $\alpha_1$ action causes marked peripheral vasoconstriction. This triggers a **reflex bradycardia** via the baroreceptor reflex, which often offsets its direct stimulatory effects on the heart rate. * **Ephedrine:** This is a mixed-acting sympathomimetic. It is significantly **less potent** than adrenaline because it acts partly by releasing endogenous noradrenaline and has a lower affinity for adrenergic receptors. * **Salbutamol:** This is a **selective $\beta_2$ agonist**. While it can cause tachycardia (via direct $\beta_2$ stimulation in the heart and reflex tachycardia due to vasodilation), it lacks the powerful $\beta_1$ and $\alpha$ mediated cardiac support provided by adrenaline. **High-Yield NEET-PG Pearls:** * **Drug of Choice (DOC):** Adrenaline is the DOC for **Anaphylactic Shock** (1:1000 IM) and **Cardiac Arrest** (1:10,000 IV). * **Vasomotor Reversal of Dale:** This phenomenon occurs when adrenaline is given after an $\alpha$-blocker, resulting in a fall in BP due to unopposed $\beta_2$ action. * **Metabolism:** Catecholamines like adrenaline are rapidly degraded by **COMT and MAO**, explaining their short duration of action.

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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