Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 271: Which beta-blocker increases HDL-cholesterol?

A. Celiprolol (Correct Answer)
B. Nebivolol
C. Carvedilol
D. Metoprolol

Explanation: ### Explanation **Correct Option: A. Celiprolol** Beta-blockers typically have an adverse effect on lipid profiles, often increasing triglycerides and decreasing HDL-cholesterol (the "good" cholesterol) [2]. However, **Celiprolol** is a unique, third-generation cardioselective beta-1 antagonist with **partial beta-2 agonist activity** [1]. This intrinsic sympathomimetic activity (ISA) at beta-2 receptors promotes peripheral vasodilation and stimulates lipoprotein lipase, which leads to an **increase in HDL-cholesterol** and a reduction in triglycerides [3]. This makes it metabolically "friendly" compared to traditional beta-blockers. **Analysis of Incorrect Options:** * **B. Nebivolol:** While it is a highly selective beta-1 blocker with nitric oxide (NO)-mediated vasodilatory properties, it is generally considered **lipid-neutral** [1]. It does not significantly increase HDL. * **C. Carvedilol:** This is a non-selective beta and alpha-1 blocker. While it is metabolically superior to older drugs like Propranolol (it does not worsen insulin resistance or significantly lower HDL), it does not actively increase HDL levels like Celiprolol [1]. * **D. Metoprolol:** A standard second-generation cardioselective beta-1 blocker. It is notorious for traditional beta-blocker side effects, including a **decrease in HDL** and an increase in plasma triglycerides. **High-Yield Clinical Pearls for NEET-PG:** * **Metabolic Neutrality:** Third-generation beta-blockers (Celiprolol, Carvedilol, Nebivolol) are preferred in patients with Diabetes or Dyslipidemia [1]. * **ISA Property:** Drugs with Intrinsic Sympathomimetic Activity (e.g., Pindolol, Celiprolol) cause less bradycardia and fewer lipid disturbances [3]. * **Celiprolol's Unique Profile:** It is also a weak alpha-2 antagonist, further contributing to its vasodilatory effect [3]. It is often the drug of choice in patients with **Vascular Ehlers-Danlos Syndrome**.

Question 272: Which of the following drugs is least useful in the management of congestive cardiac failure?

A. Bucindolol
B. Pimobendan
C. Vesnarinone
D. Trimetazidine (Correct Answer)

Explanation: **Explanation:** The management of Congestive Cardiac Failure (CCF) focuses on improving hemodynamics, reducing remodeling, and enhancing myocardial contractility [2]. **Why Trimetazidine is the correct answer:** Trimetazidine is a **metabolic modulator** (pFOX inhibitor) that shifts myocardial metabolism from fatty acid oxidation to glucose oxidation. While it is highly effective in managing **chronic stable angina** by optimizing oxygen utilization, it has no direct effect on cardiac contractility, preload, or afterload. Large-scale clinical trials have not established it as a standard therapy for the management of heart failure, making it the "least useful" among the given options. **Analysis of other options:** * **Bucindolol:** A non-selective **beta-blocker** with mild alpha-blocking properties. Beta-blockers (like Carvedilol, Metoprolol, and Bisoprolol) are a cornerstone of CCF management as they reduce remodeling and mortality [1], [2]. * **Pimobendan:** A **calcium sensitizer** and PDE3 inhibitor. It acts as an "inodilator," increasing cardiac contractility and causing vasodilation, used specifically in acute or refractory heart failure [1], [2]. * **Vesnarinone:** An **ionotropic agent** with multiple mechanisms (PDE3 inhibition and sodium channel modulation) [2]. Though its long-term use is limited by side effects, it is pharmacologically classified as a drug for heart failure. **High-Yield Clinical Pearls for NEET-PG:** * **Beta-blockers in CCF:** Only specific ones (Bisoprolol, Carvedilol, Metoprolol succinate, and Nebivolol) are proven to reduce mortality [1]. * **Inodilators:** Drugs like Milrinone and Pimobendan are used in decompensated CCF but may increase the risk of arrhythmias [2]. * **Trimetazidine Side Effect:** It can cause **Parkinsonian symptoms** (tremors, rigidity) in elderly patients, a frequent "catch" in pharmacology questions.

Question 273: Which angiotensin receptor blocker also has PPAR gamma activity?

A. Candesartan
B. Valsartan
C. Telmisartan (Correct Answer)
D. Losartan

Explanation: **Explanation:** **Telmisartan** is unique among Angiotensin II Receptor Blockers (ARBs) because it acts as a **selective partial agonist of Peroxisome Proliferator-Activated Receptor gamma (PPAR-γ)**. 1. **Why Telmisartan is correct:** Structurally, telmisartan resembles ligands that bind to PPAR-γ (a nuclear receptor primarily involved in glucose and lipid metabolism). By activating PPAR-γ, telmisartan improves insulin sensitivity, reduces glucose levels, and exerts anti-inflammatory effects. This makes it particularly beneficial for hypertensive patients with **metabolic syndrome or Type 2 Diabetes Mellitus**. 2. **Why other options are incorrect:** * **Losartan:** Known for its unique **uricosuric property** (inhibits URAT1 transporter), making it the drug of choice for hypertensive patients with Gout. It does not have significant PPAR-γ activity. * **Candesartan & Valsartan:** These are potent, selective AT1 receptor blockers but lack the structural configuration required to modulate the PPAR-γ receptor. They are primarily used for hypertension and heart failure (especially Valsartan in post-MI patients). **High-Yield Clinical Pearls for NEET-PG:** * **Longest Half-life:** Telmisartan has the longest half-life (~24 hours) among all ARBs, allowing for once-daily dosing. * **Dual Benefit:** It is often referred to as a "Metabosartan" due to its dual action on blood pressure and metabolic parameters. * **Teratogenicity:** Like ACE inhibitors, all ARBs are **contraindicated in pregnancy** (Category D) as they cause fetal renal anomalies and oligohydramnios. * **Side Effect:** Unlike ACE inhibitors, ARBs do not cause a dry cough because they do not interfere with Bradykinin metabolism.

Question 274: All the following drugs are used in the management of pheochromocytoma except?

A. Prazosin
B. Atenolol (Correct Answer)
C. Nitroprusside
D. Metyrosine

Explanation: **Explanation:** The management of **Pheochromocytoma** requires a specific sequence of pharmacological blockade to prevent a hypertensive crisis. **Why Atenolol is the correct answer:** Atenolol is a selective **$\beta_1$-blocker**. In pheochromocytoma, the tumor secretes massive amounts of catecholamines. If a $\beta$-blocker is administered alone (or before $\alpha$-blockade), it blocks $\beta_2$-mediated vasodilation in skeletal muscle. This leaves the $\alpha$-receptors unopposed, leading to exaggerated vasoconstriction and a life-threatening rise in blood pressure (**"unopposed alpha stimulation"**). Therefore, $\beta$-blockers are contraindicated as monotherapy. **Analysis of incorrect options:** * **Prazosin:** A selective $\alpha_1$-blocker used to control hypertension. In clinical practice, **Phenoxybenzamine** (non-selective, irreversible $\alpha$-blocker) is the traditional drug of choice for preoperative preparation. * **Nitroprusside:** A potent vasodilator used intravenously to manage **hypertensive crises** during surgical resection of the tumor. * **Metyrosine:** An inhibitor of the enzyme **tyrosine hydroxylase** (the rate-limiting step in catecholamine synthesis). It is used in inoperable or metastatic cases to reduce the total catecholamine pool. **NEET-PG High-Yield Pearls:** 1. **Golden Rule:** Always give **Alpha blockers BEFORE Beta blockers** (usually 7–14 days prior to surgery). 2. **Drug of Choice (Pre-op):** Phenoxybenzamine. 3. **Intra-operative HTN:** Sodium Nitroprusside or Phentolamine. 4. **Intra-operative Arrhythmia:** Lidocaine or Esmolol (only after $\alpha$-blockade). 5. **Metyrosine Mechanism:** Inhibits Tyrosine $\rightarrow$ DOPA conversion.

Question 275: Which of the following is a Class III antiarrhythmic drug?

A. Amiodarone (Correct Answer)
B. Phenytoin
C. Propafenone
D. Pindolol

Explanation: **Explanation:** The classification of antiarrhythmic drugs is based on the **Vaughan-Williams classification**, which categorizes drugs according to their primary mechanism of action on the cardiac action potential. **A. Amiodarone (Correct):** This is a prototypical **Class III** antiarrhythmic. Class III drugs primarily act by **blocking potassium (K+) channels**, which prolongs the duration of the action potential and the effective refractory period (ERP) without significantly affecting the conduction velocity. While Amiodarone also possesses Class I, II, and IV properties, it is categorized as Class III. **B. Phenytoin:** This is a **Class Ib** antiarrhythmic. It blocks sodium (Na+) channels and is specifically used in treating digitalis-induced arrhythmias. **C. Propafenone:** This belongs to **Class Ic**. It is a potent sodium channel blocker that significantly slows conduction velocity (prolonging the QRS complex) with minimal effect on the action potential duration. **D. Pindolol:** This is a **Class II** antiarrhythmic. It is a non-selective beta-blocker with intrinsic sympathomimetic activity (ISA), used to decrease sympathetic stimulation to the heart. **High-Yield NEET-PG Pearls:** * **Class III Mnemonic:** "A Big Dirty Dog Is Scary" (**A**miodarone, **B**retylium, **D**ronedarone, **D**ofetilide, **I**butilide, **S**otalol). * **Amiodarone Side Effects:** Pulmonary fibrosis, thyroid dysfunction (hypo/hyper due to high iodine content), corneal microdeposits, and "blue-gray" skin discoloration. * **ECG Change:** Class III drugs typically cause **QT interval prolongation**, which carries a risk of Torsades de Pointes (though the risk is lower with Amiodarone compared to Sotalol).

Question 276: Which of the following GPIIb/IIIa antagonists is safe in renal failure?

A. Abciximab (Correct Answer)
B. Eptifibatide
C. Tirofiban
D. Eptifibatide and Tirofiban

Explanation: **Explanation:** **Glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors** are potent antiplatelet agents that block the final common pathway of platelet aggregation by preventing the binding of fibrinogen to its receptor. **1. Why Abciximab is the correct answer:** Abciximab is a chimeric monoclonal antibody fragment. Unlike other drugs in this class, it is **not primarily cleared by the kidneys**. It is eliminated via the reticuloendothelial system and through binding to platelets (where it remains for the life of the platelet). Because its clearance is independent of renal function, **no dose adjustment is required in renal failure**, making it the safest choice for patients with significant renal impairment. **2. Why the other options are incorrect:** * **Eptifibatide (Option B):** This is a synthetic cyclic peptide. It is primarily excreted by the kidneys. In patients with renal impairment (CrCl < 50 mL/min), the dose must be reduced, and it is contraindicated in patients on dialysis. * **Tirofiban (Option C):** This is a non-peptide small molecule. Like eptifibatide, it is predominantly cleared renally. Dose reduction is mandatory if CrCl is < 60 mL/min. * **Option D:** Since both Eptifibatide and Tirofiban require renal dose adjustment, this option is incorrect. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Blocks the binding of fibrinogen and von Willebrand factor to GPIIb/IIIa receptors. * **Reversibility:** Abciximab has a long biological half-life (platelet function recovers in 24–48 hours), whereas Eptifibatide and Tirofiban are short-acting (recovery in 4–8 hours). * **Side Effects:** The most common side effect for all GPIIb/IIIa inhibitors is **bleeding** and **thrombocytopenia**. * **Monitoring:** Always monitor platelet counts within 2–4 hours of starting these drugs.

Question 277: Tolazoline is:

A. Thrombin inhibitor
B. Vasodilator (Correct Answer)
C. Vasoconstrictor
D. Antispasmodic

Explanation: **Explanation:** **Tolazoline** is a non-selective **alpha-adrenergic receptor antagonist** (blocking both $\alpha_1$ and $\alpha_2$ receptors). By blocking $\alpha_1$ receptors on vascular smooth muscle, it prevents catecholamine-induced vasoconstriction, leading to direct peripheral **vasodilation**. It also possesses histamine-like, cholinergic, and sympathomimetic properties, which further contribute to its vasodilatory effects. **Analysis of Options:** * **A. Thrombin inhibitor:** These are anticoagulants (e.g., Dabigatran, Heparin). Tolazoline has no effect on the coagulation cascade. * **C. Vasoconstrictor:** This is the opposite of Tolazoline’s action. Alpha-blockers decrease peripheral resistance, whereas alpha-agonists (like Phenylephrine) cause vasoconstriction. * **D. Antispasmodic:** These drugs (e.g., Hyoscine, Dicyclomine) act primarily on muscarinic receptors in the GI or urinary tract. Tolazoline is primarily a cardiovascular agent. **NEET-PG High-Yield Pearls:** 1. **Clinical Use:** Historically used in **Persistent Pulmonary Hypertension of the Newborn (PPHN)** to reduce pulmonary vascular resistance, though it has largely been replaced by inhaled Nitric Oxide. 2. **Structure:** It is an **imidazoline** derivative, chemically related to Phentolamine. 3. **Adverse Effects:** It can stimulate gastric acid secretion (histamine-like effect), potentially leading to **gastrointestinal hemorrhage**, and may cause tachycardia. 4. **Diagnostic Use:** It was previously used in the "Tolazoline test" during cardiac catheterization to assess the reversibility of pulmonary hypertension.

Question 278: Which of the following drugs is NOT used for the treatment of hypertensive emergencies?

A. Phentolamine
B. Fenoldopam
C. Sodium Nitroprusside
D. Enalapril (Correct Answer)

Explanation: **Explanation:** The primary goal in a **hypertensive emergency** (severely elevated BP with evidence of end-organ damage) is the rapid, controlled reduction of blood pressure using **intravenous (IV)** medications. **Why Enalapril is the correct answer:** Enalapril is an **oral** ACE inhibitor. In emergency settings, oral drugs are avoided because their onset of action is slow and their absorption can be unpredictable. While its active metabolite, **Enalaprilat**, is available as an IV formulation and can be used in emergencies, **Enalapril** itself is reserved for the long-term management of chronic hypertension (Hypertensive Urgency). **Analysis of Incorrect Options:** * **Phentolamine:** A non-selective alpha-blocker administered IV. It is the drug of choice for hypertensive crises associated with **Catecholamine excess** (e.g., Pheochromocytoma, Tyramine reaction, or Cocaine overdose). * **Fenoldopam:** A selective **Dopamine D1 receptor agonist**. It causes systemic vasodilation and maintains/increases renal perfusion, making it ideal for hypertensive emergencies in patients with renal insufficiency. * **Sodium Nitroprusside:** A potent, rapid-acting mixed (arterial and venous) vasodilator. Though historically the "gold standard," its use is now limited due to the risk of **Cyanide/Thiocyanate toxicity**. **NEET-PG High-Yield Pearls:** * **Drug of Choice (DOC):** **Labetalol** is generally the first-line agent for most hypertensive emergencies, including aortic dissection and pregnancy-induced hypertension (Eclampsia). * **Esmolol:** Preferred in aortic dissection or perioperative hypertension due to its ultra-short half-life (~9 minutes). * **Nitroglycerin:** The DOC for hypertensive emergencies associated with **Acute Coronary Syndrome** or Pulmonary Edema. * **Avoid Nifedipine (Sublingual):** It is contraindicated in emergencies as it can cause a precipitous drop in BP, leading to reflex tachycardia and cerebral/myocardial ischemia.

Question 279: Which of the following statements is NOT true regarding sotalol?

A. It is a non-selective beta-blocker.
B. It prolongs the action potential duration throughout the heart.
C. It is excreted through bile following hepatic metabolism. (Correct Answer)
D. Polymorphic ventricular tachycardia is a common problem.

Explanation: ### Explanation **Sotalol** is a unique antiarrhythmic agent that possesses both **Class II** (beta-blocking) and **Class III** (potassium channel blocking) properties. **1. Why Option C is the correct answer (The False Statement):** Unlike many beta-blockers that undergo extensive hepatic metabolism (like propranolol), sotalol is **not metabolized by the liver**. It is highly water-soluble and is excreted **unchanged by the kidneys**. Therefore, its dosage must be strictly adjusted in patients with renal impairment to prevent toxicity. It is not excreted through bile. **2. Analysis of Incorrect Options (True Statements):** * **Option A:** Sotalol is a **non-selective beta-adrenergic receptor antagonist** (blocks both $\beta_1$ and $\beta_2$ receptors). It lacks intrinsic sympathomimetic activity (ISA) and membrane-stabilizing activity. * **Option B:** Its Class III action involves blocking the rapid component of the delayed rectifier potassium current ($I_{Kr}$). This leads to a delay in repolarization, thereby **prolonging the action potential duration (APD)** and the effective refractory period (ERP) in both atrial and ventricular tissues. * **Option D:** By prolonging the APD, sotalol increases the **QT interval** on the ECG. This predisposes patients to **Torsades de Pointes** (a form of polymorphic ventricular tachycardia), especially in the setting of hypokalemia or bradycardia. ### Clinical Pearls for NEET-PG: * **Vaughan-Williams Classification:** Sotalol is the classic example of a drug with dual Class II and Class III properties. * **Reverse Use-Dependence:** The Class III effect (QT prolongation) of sotalol is most pronounced at **slower heart rates**, which paradoxically increases the risk of arrhythmias during rest or sleep. * **Indications:** Used for maintaining sinus rhythm in atrial fibrillation and treating life-threatening ventricular arrhythmias. * **Contraindication:** Avoid in patients with a baseline QTc >450 ms or significant renal failure (CrCl <10 ml/min).

Question 280: An increase in heart rate and renin release seen in patients of CHF can be overcome by which of the following drugs?

A. Minoxidil
B. Metoprolol (Correct Answer)
C. Metolazone
D. Milrinone

Explanation: ### Explanation The correct answer is **Metoprolol**. **Mechanism and Rationale:** In Chronic Heart Failure (CHF), the body compensates for reduced cardiac output by activating the **Sympathetic Nervous System (SNS)**. This leads to a chronic increase in catecholamines, which act on: 1. **$\beta_1$ receptors in the heart:** Causing tachycardia (increased heart rate). 2. **$\beta_1$ receptors in the Juxtaglomerular (JG) apparatus:** Stimulating renin release, which activates the RAAS pathway, leading to fluid retention and cardiac remodeling. **Metoprolol** is a cardioselective $\beta_1$-blocker. By antagonizing these receptors, it directly reduces the heart rate and inhibits the release of renin. This "unloads" the heart and prevents the long-term deleterious effects of chronic sympathetic overactivity, which is why $\beta$-blockers (specifically Metoprolol succinate, Bisoprolol, and Carvedilol) are cornerstones in reducing mortality in CHF. **Analysis of Incorrect Options:** * **A. Minoxidil:** A potent vasodilator that acts by opening $K^+$ channels. It actually causes **reflex tachycardia** and stimulates renin release due to the drop in blood pressure, worsening the symptoms mentioned. * **C. Metolazone:** A thiazide-like diuretic. While it helps in fluid overload, it can lead to volume depletion, which may indirectly **increase** renin release via the macula densa mechanism. * **D. Milrinone:** A PDE-3 inhibitor (Inodilator). It increases cAMP, which **increases** heart rate and contractility. It is used for acute decompensated HF but does not inhibit renin release. **High-Yield Clinical Pearls for NEET-PG:** * **Mortality Benefit in CHF:** Only three $\beta$-blockers are proven to reduce mortality: **Metoprolol succinate, Bisoprolol, and Carvedilol.** * **Contraindication:** $\beta$-blockers should never be started during a phase of *acute* decompensation; they are initiated once the patient is stable (euvolemic). * **Renin Inhibition:** Apart from $\beta$-blockers, Aliskiren (Direct Renin Inhibitor) also inhibits renin, but it does not decrease the heart rate.

Practice by Chapter

Antihypertensive Agents

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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

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Drugs Used in Pulmonary Hypertension

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Drugs Used in Shock

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Cardiovascular Effects of Non-Cardiovascular Drugs

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