Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 831: Which drug is NOT useful in congestive heart failure?

A. Adrenaline (Correct Answer)
B. Digoxin
C. Hydrochlorothiazide
D. Enalapril

Explanation: **Explanation:** In Congestive Heart Failure (CHF), the primary goal is to improve cardiac output while reducing the workload on an already failing heart. **Why Adrenaline (Option A) is the correct answer:** Adrenaline is a potent non-selective alpha and beta-adrenergic agonist. While it increases myocardial contractility (positive inotropy), it significantly increases heart rate (positive chronotropy) and peripheral vascular resistance. This leads to a massive increase in **myocardial oxygen demand** and **afterload**, which can precipitate arrhythmias and worsen myocardial ischemia in a failing heart. Therefore, it has no role in the long-term management of CHF. **Why the other options are used in CHF:** * **Digoxin (Option B):** A cardiac glycoside that inhibits the Na+/K+ ATPase pump, increasing intracellular calcium. It provides **positive inotropic** support and controls heart rate (especially in patients with concomitant Atrial Fibrillation). * **Hydrochlorothiazide (Option C):** A thiazide diuretic used to reduce fluid overload (preload), thereby relieving symptoms of pulmonary and peripheral edema. * **Enalapril (Option D):** An ACE inhibitor that is a cornerstone of CHF therapy. It reduces both **preload and afterload** and, most importantly, inhibits cardiac remodeling, which reduces mortality. **High-Yield Clinical Pearls for NEET-PG:** * **Mortality Benefit:** ACE inhibitors (Enalapril), Beta-blockers (Carvedilol, Metoprolol), Spironolactone, and ARNIs (Sacubitril/Valsartan) are proven to decrease mortality in CHF. * **Symptomatic Relief Only:** Digoxin and Diuretics improve symptoms and reduce hospitalizations but do **not** decrease mortality. * **Inotropic Support:** For acute decompensated heart failure, **Dobutamine** or **Milrinone** are preferred over Adrenaline as they are less likely to cause extreme tachycardia and vasoconstriction.

Question 832: Which of the following antihypertensive drugs is contraindicated in the treatment of hypertension during pregnancy?

A. Nifedipine
B. Captopril (Correct Answer)
C. Methyldopa
D. Hydralazine

Explanation: The correct answer is **Captopril (Option B)**. Captopril is an **ACE Inhibitor (ACEI)**. ACE inhibitors and Angiotensin Receptor Blockers (ARBs) are strictly contraindicated throughout pregnancy (FDA Category D) [1, 2]. The underlying medical concept is their **teratogenic potential**, particularly during the second and third trimesters [1, 2]. They interfere with fetal renal development, leading to **fetal renal dysgenesis**, oligohydramnios, pulmonary hypoplasia, intrauterine growth restriction (IUGR), and cranial ossification defects [1, 2]. **Why the other options are incorrect:** * **Methyldopa (Option C):** Historically the drug of choice for chronic hypertension in pregnancy. It is a centrally acting alpha-2 agonist with a long-standing safety profile. * **Hydralazine (Option D):** A direct vasodilator frequently used parenterally for the management of hypertensive emergencies in pregnancy (Preeclampsia/Eclampsia). * **Nifedipine (Option A):** A Calcium Channel Blocker (CCB) commonly used as an oral maintenance therapy for hypertension in pregnancy. **NEET-PG High-Yield Pearls:** 1. **Drugs of Choice in Pregnancy:** Labetalol (often considered first-line now), Methyldopa, and Nifedipine. 2. **Teratogenic effect of ACEIs:** "Potter-like syndrome" due to oligohydramnios. 3. **Diuretics:** Generally avoided in pregnancy as they can prevent the physiological expansion of maternal plasma volume. 4. **Sodium Nitroprusside:** Avoided in pregnancy due to the risk of fetal cyanide poisoning.

Question 833: In a patient with hypertriglyceridemia and low HDL, which of the following drugs will not increase the risk of myopathy?

A. Fibric acid derivatives
B. Nicotinic acid (Correct Answer)
C. Atorvastatin
D. Lovastatin

Explanation: **Explanation:** The core concept tested here is the **risk of myopathy (rhabdomyolysis)** associated with lipid-lowering agents, particularly when used in combination. **Why Nicotinic Acid (Niacin) is the correct answer:** Nicotinic acid is highly effective for increasing HDL and lowering triglycerides. Unlike statins and fibrates, it does not significantly interfere with the metabolic pathways of muscle cells or the glucuronidation of other lipid drugs. While it has side effects like flushing and dyspepsia, it does **not** inherently increase the risk of myopathy when used as monotherapy or significantly potentiate statin-induced myopathy compared to fibrates. **Why the other options are incorrect:** * **Atorvastatin & Lovastatin (Options C & D):** Statins inhibit HMG-CoA reductase. A well-known adverse effect is **statin-associated muscle symptoms (SAMS)**, ranging from myalgia to life-threatening rhabdomyolysis. This occurs due to decreased production of Coenzyme Q10 and isoprenoids in muscle cells. * **Fibric acid derivatives (Option A):** Fibrates (especially Gemfibrozil) are notorious for causing myopathy. They inhibit the glucuronidation of statins, leading to increased statin plasma levels. Combining a fibrate with a statin exponentially increases the risk of muscle toxicity. **High-Yield Clinical Pearls for NEET-PG:** 1. **Gemfibrozil vs. Fenofibrate:** If a fibrate must be combined with a statin, **Fenofibrate** is preferred over Gemfibrozil because it does not inhibit statin metabolism as aggressively. 2. **Monitoring:** Always check **Creatine Kinase (CK)** levels in patients on statins who complain of muscle pain or weakness. 3. **Niacin Side Effect:** The most common side effect is cutaneous flushing, mediated by **Prostaglandin D2**, which can be blunted by taking **Aspirin** 30 minutes prior.

Question 834: Which of the following agents decreases preload?

A. Hydralazine
B. Nifedipine
C. Nitroglycerine (Correct Answer)
D. Losartan

Explanation: **Explanation:** The correct answer is **Nitroglycerine (C)**. **1. Why Nitroglycerine is correct:** Nitroglycerine (and other organic nitrates) acts primarily as a **venodilator**. At therapeutic doses, it releases nitric oxide, which increases cGMP in vascular smooth muscle, leading to relaxation. Because veins are more sensitive to nitrates than arteries, it causes significant peripheral venous pooling. This reduces the volume of blood returning to the heart, thereby **decreasing ventricular end-diastolic pressure (Preload)**. This reduction in preload is the primary mechanism by which nitrates decrease myocardial oxygen demand. **2. Why the other options are incorrect:** * **Hydralazine (A):** This is a selective **arteriolar dilator**. It reduces Total Peripheral Resistance (TPR), thereby decreasing **afterload**, but has minimal effect on veins or preload. * **Nifedipine (B):** As a Dihydropyridine Calcium Channel Blocker (DHP-CCB), it acts predominantly on **arterial smooth muscle**. It reduces afterload and is used for hypertension and vasospastic angina, but it does not significantly affect preload. * **Losartan (D):** This is an Angiotensin Receptor Blocker (ARB). While it causes both arterial and venous dilation to some extent, its primary clinical classification in this context is the reduction of afterload and long-term remodeling. In the specific context of "preload reduction" as a primary mechanism, Nitroglycerine is the classic pharmacological prototype. **Clinical Pearls for NEET-PG:** * **Nitrates:** Low dose = Venodilation (Preload ↓); High dose = Arteriolar dilation (Afterload ↓). * **Sodium Nitroprusside:** Decreases **both** preload and afterload (balanced vasodilator). * **Drug of Choice:** Nitroglycerine is the DOC for acute anginal attacks and acute pulmonary edema (due to rapid preload reduction). * **Side Effect:** Tachyphylaxis (tolerance) is common with nitrates; a "nitrate-free interval" of 8–12 hours is required daily.

Question 835: A patient is alert and oriented and has a BP of 110/60. In which patient would adenosine constitute appropriate initial therapy?

A. A 65-year-old man with no ischemic heart disease and wide complex tachycardia
B. A 65-year-old woman with known ischemic disease and narrow complex tachycardia (Correct Answer)
C. A 25-year-old woman with known preexcitation syndrome and narrow complex tachycardia
D. A 28-year-old man with known preexcitation syndrome and wide complex tachycardia

Explanation: **Explanation:** The core principle in managing tachyarrhythmias is determining hemodynamic stability. Since the patient is alert and has a stable BP (110/60), pharmacological intervention is appropriate before considering electrical cardioversion. **Why Option B is Correct:** Adenosine is the drug of choice for the acute termination of **Paroxysmal Supraventricular Tachycardia (PSVT)**, which typically presents as a **stable, narrow-complex tachycardia**. Even in patients with ischemic heart disease, adenosine is safe and effective for converting narrow-complex rhythms (like AVNRT or AVRT) back to sinus rhythm by transiently blocking the AV node. **Why the other options are incorrect:** * **Option A:** In a 65-year-old with **wide complex tachycardia**, the rhythm is Ventricular Tachycardia (VT) until proven otherwise. Adenosine is generally avoided in wide-complex rhythms unless the rhythm is known to be SVT with aberrancy. * **Option C:** While adenosine can be used in narrow-complex tachycardia, the presence of **Pre-excitation (WPW syndrome)** makes it risky if the rhythm is actually Atrial Fibrillation (AF). Blocking the AV node can lead to preferential conduction through the accessory pathway, potentially causing Ventricular Fibrillation. * **Option D:** In **WPW with wide complex tachycardia** (Antidromic AVRT or AF with WPW), adenosine is strictly **contraindicated**. It can cause a rapid increase in ventricular rate by blocking the AV node, leading to hemodynamic collapse. Procainamide or Ibutilide are preferred here. **Clinical Pearls for NEET-PG:** * **Mechanism:** Adenosine acts on **A1 receptors**, increasing K+ efflux and hyperpolarizing the nodal tissue. * **Half-life:** Extremely short (**<10 seconds**); must be given as a rapid IV bolus followed by a saline flush. * **Antagonist:** Theophylline and Caffeine (Adenosine receptor antagonists) decrease its efficacy. * **Side Effects:** Flushing, chest pain, and a transient sense of "impending doom."

Question 836: What is the best time to administer long-term nitrates for nocturnal angina?

A. Early morning
B. Noon
C. Evening (Correct Answer)
D. Late night

Explanation: **Explanation:** The primary goal in administering long-term nitrates (like Isosorbide mononitrate or dinitrate) is to provide therapeutic coverage during the period of maximum symptoms while preventing **nitrate tolerance**. **1. Why Evening is Correct:** For patients with **nocturnal angina**, symptoms occur during sleep. Administering the dose in the **evening** ensures peak plasma concentrations during the night. More importantly, this schedule allows for a **"nitrate-free interval"** of 10–12 hours during the day. This interval is essential to restore the sulfhydryl groups required for nitric oxide production, thereby preventing the development of tolerance. **2. Analysis of Incorrect Options:** * **Early morning (A) & Noon (B):** These timings are appropriate for patients with *exertional angina* (angina of effort) to provide coverage during daytime activities. However, for nocturnal angina, the drug levels would be too low by nighttime to be effective. * **Late night (D):** While this provides coverage for the night, it shifts the nitrate-free interval into the late afternoon/evening, which may not be as physiologically optimal as an evening dose for preventing tolerance while maintaining nocturnal efficacy. **3. High-Yield NEET-PG Pearls:** * **Nitrate Tolerance:** Occurs due to the depletion of free sulfhydryl groups and "oxidative stress." It is best prevented by a daily nitrate-free interval of **at least 10–12 hours**. * **Drug of Choice:** For *acute* episodes of any angina, Sublingual Nitroglycerin is used. For *prophylaxis* of nocturnal angina, evening administration of long-acting nitrates is preferred. * **Contraindication:** Never co-administer nitrates with **Sildenafil** (PDE-5 inhibitors) as it can lead to severe, life-threatening hypotension.

Question 837: Compared to digoxin, what is a characteristic of digitoxin?

A. Less plasma protein binding
B. Longer plasma half-life (Correct Answer)
C. Less oral absorption
D. More daily elimination

Explanation: **Explanation:** The primary difference between Digoxin and Digitoxin lies in their lipid solubility. **Digitoxin** is highly lipid-soluble (non-polar), whereas Digoxin is relatively polar. **Why the correct answer is right:** Because Digitoxin is highly lipid-soluble, it undergoes extensive **enterohepatic circulation** and is heavily bound to plasma proteins. This results in a significantly **longer plasma half-life** (approximately 5–7 days) compared to Digoxin (approximately 36–40 hours). This long half-life means Digitoxin takes much longer to reach a steady state and longer to be eliminated from the body once discontinued. **Analysis of Incorrect Options:** * **A. Less plasma protein binding:** Incorrect. Digitoxin has very high protein binding (~95%), whereas Digoxin has low binding (~25%). * **C. Less oral absorption:** Incorrect. Due to its lipid solubility, Digitoxin is almost 100% absorbed from the gut. Digoxin absorption is variable (60–80%). * **D. More daily elimination:** Incorrect. Digitoxin has a lower daily elimination rate (~10%) compared to Digoxin (~33%) because of its long half-life and extensive reabsorption. **NEET-PG High-Yield Pearls:** * **Route of Elimination:** Digoxin is primarily excreted **renally** (unchanged), making it contraindicated in renal failure. Digitoxin is primarily metabolized by the **liver**, making it the preferred cardiac glycoside in patients with renal impairment. * **Volume of Distribution:** Digoxin has a very high $V_d$ because it binds strongly to skeletal muscle (Na+/K+ ATPase). * **Toxicity:** Hypokalemia predisposes to digoxin toxicity because K+ and digoxin compete for the same binding site on the Na+/K+ ATPase pump.

Question 838: Ezetimibe acts on which of the following targets?

A. Lipoprotein lipase (LPL)
B. Peroxisome proliferator-activated receptor (PPAR)
C. Niemann-Pick C1-Like 1 (NPC1L1) protein (Correct Answer)
D. HMG-CoA reductase inhibitor

Explanation: **Explanation:** **Mechanism of Action (Why C is correct):** Ezetimibe is a lipid-lowering agent that selectively inhibits the intestinal absorption of cholesterol and related phytosterols [1]. It specifically targets and binds to the **Niemann-Pick C1-Like 1 (NPC1L1) protein**, a transport protein located on the brush border membrane of enterocytes in the small intestine [2]. By blocking this transporter, Ezetimibe reduces the delivery of intestinal cholesterol to the liver, leading to a compensatory increase in LDL-receptor expression and a subsequent decrease in circulating LDL-C levels [1]. **Analysis of Incorrect Options:** * **A. Lipoprotein lipase (LPL):** This enzyme is activated by **Fibrates** (via PPAR-α) to increase the clearance of triglyceride-rich lipoproteins [5]. * **B. Peroxisome proliferator-activated receptor (PPAR):** PPAR-α is the target for **Fibrates** (e.g., Fenofibrate), while PPAR-γ is the target for **Thiazolidinediones** (e.g., Pioglitazone). * **D. HMG-CoA reductase:** This is the rate-limiting enzyme in hepatic cholesterol synthesis, which is inhibited by **Statins** [3], [4]. **High-Yield Clinical Pearls for NEET-PG:** * **Synergy:** Ezetimibe is frequently used as an "add-on" therapy to Statins. While Statins inhibit cholesterol *synthesis*, Ezetimibe inhibits cholesterol *absorption* (Dual inhibition) [1]. * **Effect on Lipids:** Its primary effect is a 15–20% reduction in **LDL**. It has minimal effects on HDL or Triglycerides [1]. * **Side Effects:** Generally well-tolerated; however, it may cause increased hepatic transaminases when used with statins. * **Vytorin:** A fixed-dose combination of Ezetimibe + Simvastatin.

Question 839: Which local anesthetic agent is also used as an antiarrhythmic agent?

A. Bupivacaine
B. Lignocaine (Correct Answer)
C. Cocaine
D. Chlorprocaine

Explanation: **Explanation:** **Lignocaine (Lidocaine)** is the correct answer because it belongs to **Class IB antiarrhythmics**. It acts by blocking voltage-gated sodium channels in the inactivated state. In cardiac tissue, it specifically targets ventricular myocytes with long action potentials, making it the drug of choice for treating **ventricular arrhythmias** (especially those associated with acute myocardial infarction or digitalis toxicity). Unlike other local anesthetics, it has a rapid onset and a short duration of action, allowing for precise titration via intravenous infusion. **Analysis of Incorrect Options:** * **Bupivacaine:** While a potent local anesthetic, it is highly **cardiotoxic**. It binds tightly to cardiac sodium channels and dissociates slowly during diastole ("fast in, slow out" kinetics), which can induce fatal ventricular arrhythmias and cardiac arrest. * **Cocaine:** It is a local anesthetic with sympathomimetic properties. It inhibits the reuptake of norepinephrine, leading to hypertension, tachycardia, and coronary vasospasm. It is never used as an antiarrhythmic. * **Chlorprocaine:** This is an ester-type local anesthetic with a very short half-life due to rapid hydrolysis by plasma pseudocholinesterase. It lacks significant antiarrhythmic properties. **High-Yield Clinical Pearls for NEET-PG:** * **Class IB Specificity:** Lignocaine is ineffective against atrial arrhythmias because atrial action potentials are too short to allow significant binding to inactivated sodium channels. * **Toxicity:** Overdose leads to **CNS side effects** first (perioral numbness, tremors, seizures) before cardiovascular collapse. * **Route:** For arrhythmias, it is given **IV** (due to high first-pass metabolism); for local anesthesia, it is used topically or via infiltration. * **Adrenaline Interaction:** Adrenaline is often added to Lignocaine in local anesthesia to prolong its duration and reduce systemic absorption, but it is **never** added when Lignocaine is used as an antiarrhythmic.

Question 840: All of the following are useful in the intravenous therapy for hypertensive emergencies except:

A. Fenoldopam (Correct Answer)
B. Urapidil
C. Enalaprilat
D. Nifedipine

Explanation: **Explanation:** In a hypertensive emergency, the goal is to reduce blood pressure rapidly but controlledly using **intravenous (IV)** medications to prevent or limit end-organ damage. **Why Fenoldopam is the "Except" (Correct Answer):** Actually, there is a common misconception in this question's framing. In standard clinical practice, **Fenoldopam, Urapidil, and Enalaprilat** are all administered via the **IV route** and are indicated for hypertensive emergencies. However, **Nifedipine** (Option D) is the most appropriate "except" because it is primarily an **oral** medication. Specifically, the **sublingual** use of Nifedipine is strictly contraindicated in hypertensive emergencies as it causes an unpredictable, precipitous drop in BP, leading to reflex tachycardia and potential cerebral or myocardial ischemia. *(Note: If the provided key marks Fenoldopam as correct, it is likely due to a technical error in the question source, as Fenoldopam is a classic IV drug for this condition. In NEET-PG, always prioritize Nifedipine as the drug to avoid.)* **Analysis of Options:** * **Fenoldopam:** A selective dopamine $D_1$ receptor agonist. It causes systemic vasodilation and maintains renal perfusion (natriuretic). Given **IV**. * **Urapidil:** A dual-action agent ($\alpha_1$ blocker and $5-HT_{1A}$ agonist). Widely used **IV** for perioperative hypertension and emergencies. * **Enalaprilat:** The active metabolite of Enalapril; it is the only ACE inhibitor available for **IV** use. * **Nifedipine:** A short-acting DHP-CCB. Its rapid-onset oral/sublingual forms are **avoided** in emergencies due to lack of titration control. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC)** for most hypertensive emergencies: **Labetalol** or **Nicardipine**. * **DOC for Aortic Dissection:** Esmolol + Nitroprusside (to reduce shear stress). * **DOC for Hypertensive Emergency with Renal Failure:** Fenoldopam. * **DOC for Pheochromocytoma:** Phentolamine. * **Avoid:** Sublingual Nifedipine.

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