Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 921: Which drug is not contraindicated in a pregnant lady for hypertension?

A. Sodium nitroprusside
B. Hydralazine (Correct Answer)
C. ACE inhibitors
D. Indapamide

Explanation: In the management of hypertension during pregnancy, the primary goal is to ensure maternal safety without compromising fetal development or placental perfusion. **Hydralazine** is a direct-acting vasodilator that has been used for decades to manage hypertensive emergencies in pregnancy (e.g., pre-eclampsia) [2, 3]. It is considered safe because it does not have teratogenic effects and maintains adequate uterine blood flow [1]. **Analysis of Options:** * **Hydralazine (Correct):** It is a preferred parenteral agent for acute hypertensive crises in pregnancy. Along with **Labetalol** (drug of choice) and **Methyldopa** (safest for chronic hypertension), it forms the mainstay of treatment. * **Sodium Nitroprusside:** Generally contraindicated because its metabolism releases **cyanide**, which can lead to fetal cyanide poisoning and death. It is only used as a last resort when all other drugs fail. * **ACE Inhibitors (e.g., Enalapril):** These are strictly contraindicated (Category X/D). They cause **fetal dysgenesis**, including renal failure, oligohydramnios, skull hypoplasia, and pulmonary hypoplasia. * **Indapamide (Diuretics):** Diuretics are generally avoided in pregnancy because they can decrease maternal plasma volume, potentially leading to **placental hypoperfusion** and intrauterine growth restriction (IUGR). **NEET-PG High-Yield Pearls:** 1. **Drug of Choice (Chronic HTN in Pregnancy):** Oral Methyldopa (centrally acting alpha-2 agonist). 2. **Drug of Choice (Acute Hypertensive Crisis/Pre-eclampsia):** IV Labetalol is currently preferred over Hydralazine due to fewer side effects like reflex tachycardia. 3. **Teratogenic Risk:** ACE inhibitors and ARBs are most dangerous during the 2nd and 3rd trimesters due to their effects on the fetal renin-angiotensin system. 4. **Calcium Channel Blockers:** Nifedipine (long-acting) is also safe and frequently used.

Question 922: Which drug is contraindicated in hypertriglyceridemia?

A. Fibrates
B. Simvastatin
C. Niacin
D. Cholestyramine (Correct Answer)

Explanation: The correct answer is **Cholestyramine**. **Mechanism and Contraindication:** Cholestyramine is a **Bile Acid Sequestrant (BAS)** [2]. It works by binding bile acids in the intestine, preventing their enterohepatic circulation [2]. This depletion of bile acids triggers the liver to convert more cholesterol into bile acids, thereby upregulating LDL receptors and lowering serum LDL. However, the compensatory increase in hepatic cholesterol synthesis is accompanied by a **concomitant increase in VLDL (Very Low-Density Lipoprotein) production** [1]. In patients with pre-existing hypertriglyceridemia, this leads to a significant rise in serum triglyceride (TG) levels, potentially precipitating acute pancreatitis. Therefore, BAS are contraindicated if baseline TG levels are >300 mg/dL [1]. **Analysis of Incorrect Options:** * **A. Fibrates (e.g., Fenofibrate):** These are the **drugs of choice** for severe hypertriglyceridemia. They activate PPAR-α, increasing lipoprotein lipase (LPL) activity and decreasing TG levels. * **B. Simvastatin:** Statins primarily lower LDL but also have a modest TG-lowering effect (10–30%). They are not contraindicated; rather, they are often used in mixed dyslipidemia. * **C. Niacin (Nicotinic Acid):** This is one of the most effective drugs for increasing HDL and is also very effective at lowering triglycerides by inhibiting lipolysis in adipose tissue. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of choice for isolated hypertriglyceridemia:** Fibrates. * **Side effect of Cholestyramine:** Malabsorption of fat-soluble vitamins (A, D, E, K) and drugs like Warfarin or Digoxin. * **Most common side effect of Niacin:** Cutaneous flushing (mediated by Prostaglandin D2; prevented by Aspirin). * **Statin + Fibrate combination:** Increases the risk of **myopathy/rhabdomyolysis** (Gemfibrozil is more risky than Fenofibrate when combined with statins) [1].

Question 923: Headache is a commonly observed side effect of which anti-anginal drug class?

A. Beta blockers
B. Nitrates (Correct Answer)
C. Trimetazidine
D. Potassium channel openers

Explanation: **Explanation:** **Why Nitrates are the Correct Answer:** Nitrates (e.g., Nitroglycerin, Isosorbide dinitrate) act as prodrugs that release **Nitric Oxide (NO)**. NO activates guanylyl cyclase, increasing cGMP levels, which leads to smooth muscle relaxation. While this effectively causes venodilation (reducing preload) and coronary vasodilation, it also causes significant **vasodilation of the meningeal and extracranial blood vessels**. This rapid stretching of the vessel walls and activation of perivascular pain fibers results in a characteristic throbbing headache, often referred to as a "Nitrate headache." **Analysis of Incorrect Options:** * **Beta blockers (A):** These drugs decrease heart rate and contractility. Their common side effects include bradycardia, fatigue, and bronchospasm, but they are actually used for migraine *prophylaxis*, not as a cause of headache. * **Trimetazidine (C):** A metabolic modulator that shifts myocardial metabolism from fatty acid oxidation to glucose oxidation. It is generally well-tolerated; its unique side effects are Parkinsonian-like symptoms (tremors/rigidity). * **Potassium channel openers (D):** While drugs like Nicorandil can cause headaches due to their nitrate-like moiety, Nitrates are the classic, more "commonly observed" prototype for this side effect in standard pharmacology curricula. **High-Yield Clinical Pearls for NEET-PG:** * **Nitrate Tolerance:** Continuous exposure leads to a loss of efficacy. A "nitrate-free interval" (8–12 hours) is essential to restore sensitivity. * **Monday Disease:** Historically, dynamite factory workers exposed to nitrates during the week developed headaches that disappeared over the weekend (due to tolerance) and returned on Monday. * **Contraindication:** Never co-administer Nitrates with **Sildenafil (PDE-5 inhibitors)**, as this can lead to catastrophic hypotension.

Question 924: Alpha-methyldopa is primarily used for which condition?

A. Pregnancy-induced hypertension (Correct Answer)
B. Renovascular hypertension
C. First-line agent in hypertension
D. Refractory hypertension

Explanation: **Explanation:** **Alpha-methyldopa** is a centrally acting sympatholytic agent. It acts as a prodrug, converted into alpha-methylnorepinephrine, which stimulates central **alpha-2 adrenergic receptors** in the medulla. This reduces sympathetic outflow to the heart and blood vessels, leading to a decrease in peripheral vascular resistance and blood pressure. **Why Option A is Correct:** Alpha-methyldopa is considered a **first-line antihypertensive in pregnancy** (Pregnancy-induced hypertension/Preeclampsia). It has an extensive safety profile with no evidence of teratogenicity and does not compromise uteroplacental blood flow, making it safe for both the mother and the fetus. **Why Other Options are Incorrect:** * **Option B:** In renovascular hypertension (e.g., renal artery stenosis), ACE inhibitors or ARBs are typically used (unless bilateral), as the pathology is driven by the Renin-Angiotensin-Aldosterone System (RAAS). * **Option C:** It is **not** a first-line agent for general hypertension due to its side effect profile (sedation, depression). ACE inhibitors, Thiazides, or Calcium Channel Blockers are preferred. * **Option D:** Refractory hypertension usually requires potent vasodilators (like Minoxidil) or combination therapy involving diuretics and spironolactone; methyldopa is rarely potent enough for this role. **NEET-PG High-Yield Pearls:** * **Side Effects:** Positive **Coombs Test** (autoimmune hemolytic anemia), drug-induced lupus-like syndrome, and hyperprolactinemia. * **Drug of Choice (DOC):** While methyldopa is a classic choice for pregnancy, current guidelines (like ACOG) also frequently recommend **Labetalol** (often preferred due to fewer sedative effects) and **Nifedipine**. * **Contraindication:** Active hepatic disease (due to potential hepatotoxicity).

Question 925: Which of the following is the preferred antiarrhythmic agent in a patient with cardiac arrest?

A. Amiodarone (Correct Answer)
B. Lidocaine
C. Procainamide
D. Atropine

Explanation: **Explanation:** In the management of cardiac arrest due to **Shockable Rhythms** (Ventricular Fibrillation or Pulseless Ventricular Tachycardia), **Amiodarone** is the first-line antiarrhythmic agent according to the current ACLS (Advanced Cardiovascular Life Support) guidelines. **Why Amiodarone is Correct:** Amiodarone is a Class III antiarrhythmic that acts by blocking potassium channels (prolonging repolarization), but it also possesses Class I, II, and IV properties. In cardiac arrest, it is preferred because clinical trials (like the ALIVE trial) demonstrated that it improves the rate of **ROSC (Return of Spontaneous Circulation)** and survival to hospital admission compared to placebo or lidocaine. It is typically administered as a 300 mg IV/IO bolus after the third unsuccessful shock. **Why Other Options are Incorrect:** * **Lidocaine:** While Lidocaine is an acceptable alternative if Amiodarone is unavailable, it is no longer the primary choice. It is a Class Ib agent that specifically targets ischemic sodium channels. * **Procainamide:** This Class Ia agent is used for stable wide-complex tachycardia. It is not used in cardiac arrest because it requires slow infusion and can cause significant hypotension. * **Atropine:** Previously used for asystole/PEA, it was removed from the cardiac arrest algorithm in 2010 as it showed no survival benefit. It is now primarily used for symptomatic bradycardia. **High-Yield NEET-PG Pearls:** * **Drug of Choice for VF/pVT:** Amiodarone (1st line), Lidocaine (2nd line). * **Amiodarone Side Effects:** Pulmonary fibrosis, thyroid dysfunction (contains iodine), and corneal microdeposits. * **Amiodarone in WPW Syndrome:** It is the drug of choice for stable patients with WPW and atrial fibrillation. * **Maintenance:** After ROSC, an infusion of the successful antiarrhythmic is often started.

Question 926: Labetalol is an?

A. Alpha 1 blocker
B. Alpha 2 blocker
C. Alpha 1 and selective beta 1 blocker
D. Alpha 1 and non-selective beta blocker (Correct Answer)

Explanation: ### Explanation **Labetalol** is a unique antihypertensive agent that belongs to the class of **combined alpha and beta-adrenergic antagonists** [1], [4]. **1. Why Option D is Correct:** Labetalol acts as a competitive antagonist at **Alpha-1 ($\alpha_1$) receptors** and **Non-selective Beta receptors ($\beta_1$ and $\beta_2$)** [1]. * **Mechanism:** By blocking $\alpha_1$ receptors, it causes peripheral vasodilation and reduces peripheral vascular resistance [4]. Simultaneously, its $\beta$-blocking activity prevents the reflex tachycardia that usually follows vasodilation [1]. * **Potency Ratio:** The $\beta:\alpha$ blockade ratio is approximately **3:1** for oral administration and **7:1** for intravenous administration. **2. Why Other Options are Incorrect:** * **Option A & B:** Labetalol is not a pure alpha-blocker. While it blocks $\alpha_1$, it has no significant effect on $\alpha_2$ receptors (unlike Phentolamine) [3]. * **Option C:** Labetalol is **non-selective** for beta receptors. It blocks both $\beta_1$ (heart) and $\beta_2$ (bronchioles/blood vessels). A drug that is $\alpha_1$ and selective $\beta_1$ blocker is **Carvedilol** (though Carvedilol is also technically non-selective, it is often compared similarly; however, Labetalol is the classic textbook example for this specific question profile) [1]. **3. High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** Labetalol is the first-line agent for **Hypertension in Pregnancy** (Preeclampsia/Eclampsia) because it is safe for the fetus. * **Hypertensive Emergencies:** It is used IV for rapid blood pressure control (e.g., aortic dissection, pheochromocytoma) [2]. * **Side Effects:** Postural hypotension (due to $\alpha_1$ block) and bronchospasm (due to $\beta_2$ block). * **Intrinsic Sympathomimetic Activity (ISA):** Labetalol possesses mild $\beta_2$-agonist activity (partial agonist), which further aids vasodilation.

Question 927: What is the drug of choice for hypertensive crises in systemic sclerosis?

A. Beta blocker
B. Losartan
C. ACE inhibitor (Correct Answer)
D. Nitrates

Explanation: **Explanation:** **Scleroderma Renal Crisis (SRC)** is a life-threatening complication of systemic sclerosis characterized by malignant hypertension and rapid-onset renal failure. **Why ACE Inhibitors are the Drug of Choice:** The underlying pathophysiology of SRC involves severe vasospasm of the renal arteries (Raynaud’s phenomenon of the kidney), leading to renal ischemia. This ischemia triggers a massive activation of the **Renin-Angiotensin-Aldosterone System (RAAS)**. ACE inhibitors (e.g., Captopril, Enalapril) are the gold standard because they directly counteract this hyper-reninemic state by blocking the conversion of Angiotensin I to Angiotensin II. They effectively lower systemic blood pressure and, more importantly, reduce renal vascular resistance, preserving renal function even if serum creatinine is elevated. **Why other options are incorrect:** * **Beta-blockers:** These are generally **avoided** in systemic sclerosis because they can cause peripheral vasoconstriction, potentially worsening Raynaud’s phenomenon and digital ischemia. * **Losartan (ARBs):** While they act on the RAAS, clinical evidence shows they are **less effective** than ACE inhibitors in preventing dialysis or death in SRC. ACE inhibitors remain the first-line therapy. * **Nitrates:** These are primarily venous dilators and do not address the RAAS-mediated mechanism of SRC. **High-Yield Clinical Pearls for NEET-PG:** * **Captopril** is often preferred due to its short half-life, allowing for rapid dose titration. * **Steroid Warning:** High-dose corticosteroids (>15mg/day of prednisolone) are a major risk factor for triggering Scleroderma Renal Crisis. * **Prognosis:** Even if a patient requires dialysis initially, aggressive ACE inhibitor therapy can lead to renal recovery in up to 50% of cases over 1–2 years.

Question 928: A 32-year-old carpenter presents with a history of recurrent chest pain. Sublingual nitroglycerin is prescribed and advised to be taken at the onset of pain. Two weeks later, the patient reports increased chest pain intensity upon taking nitroglycerin. What is the most likely diagnosis?

A. Aortic regurgitation
B. Hypertrophic obstructive cardiomyopathy (Correct Answer)
C. Aortic dissection
D. Aortic aneurysm

Explanation: ### Explanation **Correct Answer: B. Hypertrophic obstructive cardiomyopathy (HOCM)** The clinical scenario describes a "paradoxical" response to Nitroglycerin (NTG). In most cases of angina, NTG provides relief; however, in HOCM, it can severely aggravate chest pain and outflow obstruction [1]. **Underlying Mechanism:** In HOCM, there is asymmetrical septal hypertrophy that causes dynamic left ventricular outflow tract (LVOT) obstruction. Nitroglycerin is a potent vasodilator that reduces **preload** (venous return) and **afterload**. 1. **Reduced Preload:** A smaller ventricular volume (less filling) allows the hypertrophied septum and the anterior mitral leaflet to come closer together (Systolic Anterior Motion - SAM). 2. **Increased Obstruction:** This narrows the LVOT further, worsening the obstruction and decreasing cardiac output, which leads to increased myocardial ischemia and intensified chest pain. **Analysis of Incorrect Options:** * **A. Aortic Regurgitation:** While NTG reduces afterload (which is generally beneficial in AR), it does not typically cause a paradoxical increase in pain intensity. * **C. Aortic Dissection:** NTG is generally avoided as a monotherapy because it can cause reflex tachycardia, which increases aortic wall stress ($dP/dt$), but it does not specifically worsen the "obstruction" in the manner described. * **D. Aortic Aneurysm:** Pain in an aneurysm is usually due to expansion or pressure on surrounding structures; NTG does not have a specific mechanism to increase this pain. **High-Yield Clinical Pearls for NEET-PG:** * **HOCM Contraindications:** Avoid the "3 Ds" — **D**iuretics, **D**igitalis, and **D**ilators (Nitrates/ACE inhibitors), as they worsen the LVOT gradient. * **Drug of Choice:** Beta-blockers (e.g., Propranolol) are the first-line treatment as they increase diastolic filling time and reduce the heart rate [2]. * **Physical Exam:** The murmur of HOCM **increases** with Valsalva and standing (decreased preload) and **decreases** with squatting or handgrip (increased preload/afterload).

Question 929: If a fibrinolytic drug is used for the treatment of acute myocardial infarction, what is the most likely adverse effect to occur?

A. Acute renal failure
B. Development of antiplatelet antibodies
C. Encephalitis secondary to liver dysfunction
D. Hemorrhagic stroke (Correct Answer)

Explanation: **Explanation:** **1. Why Hemorrhagic Stroke is Correct:** Fibrinolytic drugs (e.g., Streptokinase, Alteplase, Tenecteplase) work by converting plasminogen to plasmin, which degrades fibrin clots. While this is therapeutic for lysing a coronary thrombus, it creates a systemic lytic state. The most dreaded and serious complication of this systemic fibrinolysis is **intracranial hemorrhage (Hemorrhagic Stroke)**. This occurs due to the breakdown of physiological hemostatic plugs in the cerebral vasculature. It occurs in approximately 0.5% to 1% of patients receiving these agents. **2. Why the Other Options are Incorrect:** * **A. Acute renal failure:** This is not a recognized side effect of fibrinolytics. Renal failure is more commonly associated with contrast-induced nephropathy during a Primary PCI (Percutaneous Coronary Intervention). * **B. Development of antiplatelet antibodies:** Fibrinolytics target the coagulation cascade, not platelet antigens. While Streptokinase can lead to the development of *anti-streptococcal antibodies* (leading to hypersensitivity or reduced efficacy on re-administration), it does not cause antiplatelet antibodies. * **C. Encephalitis secondary to liver dysfunction:** Fibrinolytics do not cause acute liver failure or encephalitis. Neurological deficits post-fibrinolysis are almost exclusively due to bleeding. **3. High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** **Tenecteplase** is currently preferred due to its high fibrin specificity, long half-life (allowing bolus dose), and lower risk of non-cerebral bleeding. * **Streptokinase:** It is non-fibrin specific and antigenic. It should not be repeated within 6–12 months due to high antibody titers. * **Absolute Contraindications:** Previous intracranial hemorrhage, known structural cerebrovascular lesion, ischemic stroke within 3 months, or active internal bleeding. * **Antidote:** In case of life-threatening bleeding due to fibrinolytics, **Epsilon-aminocaproic acid (EACA)** or **Tranexamic acid** can be used as antidotes.

Question 930: Which of the following is an ultrashort acting beta-blocker devoid of partial agonistic or membrane stabilizing action?

A. Esmolol (Correct Answer)
B. Timolol
C. Atenolol
D. Pindolol

Explanation: **Explanation** **Esmolol** is the correct answer because it is a cardioselective (β1) antagonist characterized by its **ultrashort duration of action**. It has a half-life of approximately **9 minutes** due to its rapid hydrolysis by **red blood cell esterases**. Crucially, Esmolol lacks intrinsic sympathomimetic activity (partial agonistic action) and membrane stabilizing activity (local anesthetic effect), making it ideal for precise, minute-to-minute titration in acute settings. **Analysis of Incorrect Options:** * **Timolol (B):** A non-selective beta-blocker primarily used in glaucoma. It has a much longer half-life (approx. 4 hours) and is not considered ultrashort acting. * **Atenolol (C):** A cardioselective (β1) blocker with a long half-life (6–7 hours). It is water-soluble and excreted unchanged by the kidneys, unlike the esterase-metabolized Esmolol. * **Pindolol (D):** A non-selective beta-blocker notable for having significant **Intrinsic Sympathomimetic Activity (ISA)**, which the question specifically excludes. **High-Yield Clinical Pearls for NEET-PG:** * **Metabolism:** Esmolol is the only beta-blocker metabolized by **plasma esterases**, making it safe in patients with hepatic or renal impairment. * **Clinical Uses:** Preferred for intraoperative hypertension, supraventricular tachycardia (SVT) during surgery, and aortic dissection (to reduce shear stress). * **Mnemonic:** Remember **"Esmolol is Easy-in, Easy-out"** due to its rapid onset and offset. * **Other Ultrashort Drugs:** Similar to Esmolol, drugs like **Remifentanil** (opioid) and **Clevidipine** (CCB) are also metabolized by esterases.

Practice by Chapter

Antihypertensive Agents

Practice Questions

Drugs for Heart Failure

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Antiarrhythmic Drugs

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Antianginal Agents

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Lipid-Lowering Drugs

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Anticoagulants and Antiplatelet Drugs

Practice Questions

Thrombolytic Agents

Practice Questions

Drugs Used in Pulmonary Hypertension

Practice Questions

Drugs Used in Shock

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Cardiovascular Effects of Non-Cardiovascular Drugs

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