Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 771: Therapeutic drug monitoring of plasma concentration of antihypertensive drugs is not practiced because?

A. Determination of plasma level of these drugs is a tedious and lengthy process.
B. It is easier to measure the effect of these drugs. (Correct Answer)
C. The antihypertensive effect does not increase linearly with the dose.
D. All antihypertensive drugs are prodrugs.

Explanation: ### Explanation **1. Why Option B is Correct:** The primary goal of Therapeutic Drug Monitoring (TDM) is to guide dosage when there is no easily measurable clinical endpoint or when the drug has a narrow therapeutic index. In hypertension, the clinical effect—**Blood Pressure (BP)**—is immediate, objective, and easily measured using a simple sphygmomanometer. Since the physician can directly titrate the drug dose based on the patient’s BP response, measuring plasma concentrations is redundant, expensive, and clinically unnecessary. **2. Analysis of Incorrect Options:** * **Option A:** While some assays are complex, modern chromatography (HPLC/LC-MS) makes drug level determination routine for many substances. The lack of TDM is due to clinical utility, not technical difficulty. * **Option C:** While some drugs exhibit non-linear pharmacokinetics, this would actually be an *indication* for TDM (like Phenytoin), not a reason to avoid it. * **Option D:** Only a few antihypertensives are prodrugs (e.g., Enalapril, Methyldopa). Most commonly used drugs like Amlodipine, Atenolol, and Losartan are active in their ingested form. **3. High-Yield Clinical Pearls for NEET-PG:** * **Indications for TDM:** Narrow therapeutic index, poor correlation between dose and plasma level, lack of easily measurable clinical effect, or suspected toxicity/non-compliance. * **Classic Drugs requiring TDM:** Lithium, Digoxin, Phenytoin, Theophylline, Aminoglycosides, and Cyclosporine. * **Exceptions in CVD:** While we don't monitor levels for antihypertensives, we **do** monitor **Digoxin** (narrow therapeutic index) and **Warfarin** (via PT/INR, a surrogate marker of effect). * **Concept:** If the "pharmacological effect" is easily measurable (e.g., BP for antihypertensives, Blood Sugar for Insulin, INR for Warfarin), TDM of plasma concentration is generally not required.

Question 772: Which of the following drug classes has both anti-arrhythmic and anti-anginal properties?

A. Beta blockers (Correct Answer)
B. Nitrates
C. Rho kinase inhibitor
D. Potassium channel openers

Explanation: **Explanation:** **Beta-blockers (Option A)** are the correct choice because they possess dual therapeutic utility in managing both arrhythmias and angina pectoris. * **Anti-anginal mechanism:** They reduce myocardial oxygen demand by decreasing heart rate (negative chronotropy), blood pressure, and myocardial contractility (negative inotropy). This increases diastolic perfusion time, improving coronary blood flow. * **Anti-arrhythmic mechanism:** Classified as **Vaughan-Williams Class II** anti-arrhythmics, they block sympathetic stimulation of the heart. This decreases the slope of Phase 4 depolarization in SA/AV nodes, thereby suppressing automaticity and slowing AV conduction. **Why other options are incorrect:** * **Nitrates (Option B):** These are potent vasodilators used primarily for angina (reducing preload). They have no direct anti-arrhythmic properties and can actually cause reflex tachycardia, which may worsen certain arrhythmias. * **Rho-kinase inhibitors (Option C):** (e.g., Fasudil) These are used primarily in cerebral vasospasm or pulmonary hypertension. They do not have established roles in treating cardiac arrhythmias. * **Potassium channel openers (Option D):** (e.g., Nicorandil) These act as vasodilators for angina. While they affect potassium channels, they do not function as Class III anti-arrhythmics (which are potassium channel *blockers*). **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** Beta-blockers are the first-line treatment for chronic stable angina and for rate control in atrial fibrillation. * **Post-MI:** They are the only anti-arrhythmics proven to reduce mortality in post-myocardial infarction patients. * **Calcium Channel Blockers (Verapamil/Diltiazem):** These are the other major class that also possess both anti-anginal and anti-arrhythmic (Class IV) properties.

Question 773: Which of the following drugs commonly causes constipation?

A. Propranolol
B. Verapamil (Correct Answer)
C. Nitroglycerin
D. Captopril

Explanation: **Explanation:** **Verapamil** is a non-dihydropyridine Calcium Channel Blocker (CCB) that is notorious for causing **constipation** (seen in up to 25% of patients). The underlying mechanism involves the blockade of L-type calcium channels in the smooth muscles of the gastrointestinal tract. Calcium is essential for excitation-contraction coupling; by inhibiting calcium influx, Verapamil reduces the contractility and motility of the colonic smooth muscle, leading to delayed transit time and constipation. **Analysis of Incorrect Options:** * **Propranolol (Beta-blocker):** More commonly associated with fatigue, bradycardia, and bronchospasm. While it can occasionally cause GI upset, it is not a classic cause of constipation. * **Nitroglycerin (Nitrate):** Its primary side effects are related to systemic vasodilation, such as throbbing headaches, flushing, and orthostatic hypotension. * **Captopril (ACE Inhibitor):** Most famous for causing a dry cough (due to bradykinin accumulation), angioedema, and hyperkalemia. **High-Yield Clinical Pearls for NEET-PG:** * **Verapamil** is the CCB with the most significant negative inotropic effect; it is contraindicated in Heart Failure. * Among CCBs, **Verapamil** causes the most constipation, whereas **Nifedipine** (Dihydropyridine) is more likely to cause peripheral edema and reflex tachycardia. * **Gingival hyperplasia** is another shared side effect of CCBs (most common with Nifedipine and Verapamil). * **Drug of choice:** Verapamil is a preferred agent for prophylaxis of Cluster Headaches and for rate control in Supraventricular Tachycardia (SVT).

Question 774: Which one of the following is not an adverse effect of ACE inhibitors?

A. Cough
B. Hypokalemia (Correct Answer)
C. Angioneurotic edema
D. Skin rash

Explanation: **Explanation:** The correct answer is **Hypokalemia**. ACE inhibitors (ACEIs) actually cause **Hyperkalemia**, not hypokalemia. **Mechanism of Action & Correct Option:** ACE inhibitors block the conversion of Angiotensin I to Angiotensin II. Since Angiotensin II is a potent stimulator of **aldosterone** secretion from the adrenal cortex, its inhibition leads to decreased aldosterone levels. Aldosterone normally promotes sodium/water retention and potassium excretion in the distal tubules. Reduced aldosterone results in potassium retention, leading to **hyperkalemia**. This is a high-yield point for NEET-PG, especially when ACEIs are combined with potassium-sparing diuretics or in patients with renal impairment. **Analysis of Incorrect Options:** * **Cough (A):** This is the most common side effect (dry, irritating cough). It is caused by the accumulation of **bradykinin** and substance P in the lungs, as ACE is the enzyme responsible for their degradation. * **Angioneurotic edema (C):** A rare but life-threatening side effect also attributed to increased bradykinin levels. It involves swelling of the lips, tongue, and larynx. * **Skin rash (D):** Common with ACEIs, particularly **Captopril**, often due to its sulfhydryl group. **NEET-PG High-Yield Pearls:** * **Teratogenicity:** ACEIs are contraindicated in pregnancy as they cause fetal renal anomalies (Hypocalvaria). * **First-dose hypotension:** Common in patients on diuretics; start with a low dose at bedtime. * **Bilateral Renal Artery Stenosis:** ACEIs are strictly contraindicated as they can precipitate acute renal failure by reducing efferent arteriolar tone. * **Mnemonic for ACEI side effects (CAPTOPRIL):** **C**ough, **A**ngioedema, **P**roteinuria, **T**aste changes, **O**ther (rash), **P**regnancy contraindication, **R**enal artery stenosis contraindication, **I**ncreased potassium (**Hyperkalemia**), **L**ow BP (First-dose hypotension).

Question 775: What is the mechanism of action of Verapamil?

A. Inhibition of Ca+2 channel (Correct Answer)
B. Inhibition of Na-t channel
C. Inhibition of K+ channel
D. Block membrane repolarisation

Explanation: **Explanation:** **Verapamil** is a non-dihydropyridine **Calcium Channel Blocker (CCB)** belonging to the phenylalkylamine class. Its primary mechanism of action is the **inhibition of L-type voltage-gated calcium channels** (Option A). By blocking these channels, it prevents the inward movement of calcium ions into cardiac muscle cells and vascular smooth muscle. In the heart, this leads to negative inotropy (reduced contractility), negative chronotropy (reduced heart rate), and negative dromotropy (reduced conduction velocity, particularly at the AV node). **Analysis of Incorrect Options:** * **Option B:** Inhibition of Na+ channels is the primary mechanism of Class I antiarrhythmics (e.g., Lidocaine, Flecainide). * **Option C:** Inhibition of K+ channels is the mechanism of Class III antiarrhythmics (e.g., Amiodarone, Sotalol), which prolongs the action potential duration. * **Option D:** Verapamil actually slows the rate of depolarization in the SA and AV nodes; blocking repolarization is more characteristic of drugs that affect potassium efflux. **NEET-PG High-Yield Pearls:** * **Drug of Choice:** Verapamil is the drug of choice for terminating **Paroxysmal Supraventricular Tachycardia (PSVT)**. * **Site of Action:** Unlike Dihydropyridines (e.g., Amlodipine) which act mainly on peripheral vessels, Verapamil is **cardioselective**. * **Contraindication:** Never co-administer Verapamil with **Beta-blockers** intravenously, as it can lead to severe bradycardia or complete heart block. * **Side Effect:** A classic side effect frequently tested is **constipation** (due to calcium channel blockade in the GI smooth muscle) and gingival hyperplasia.

Question 776: Which drug is used in the management of AV block?

A. Isoprenaline (Correct Answer)
B. Dopamine
C. Atropine
D. Disopyramide

Explanation: **Explanation:** **Correct Option: A. Isoprenaline** Isoprenaline is a potent, non-selective **$̒$-adrenergic agonist** ($̒_1$ and $̒_2$). Its action on $̒_1$ receptors in the heart results in significant positive chronotropic (increased heart rate) and dromotropic (increased conduction velocity) effects [1]. By enhancing conduction through the AV node and increasing the idioventricular rate, it is used as a temporary pharmacological measure to manage high-grade AV block and symptomatic bradycardia until a permanent pacemaker can be inserted [1], [4]. **Analysis of Incorrect Options:** * **B. Dopamine:** While Dopamine has $̒_1$ effects at moderate doses, it is primarily used for cardiogenic or septic shock due to its $̡_1$ (vasoconstriction) and dopaminergic (renal vasodilation) properties [3]. It is not the first-line choice specifically for reversing AV block. * **C. Atropine:** Atropine is an anticholinergic used for sinus bradycardia [2]. While it can improve AV conduction by blocking vagal tone, it is often ineffective in **Type II Second-degree or Third-degree (Complete) AV blocks**, especially if the block is infra-nodal (within the Bundle of His). * **D. Disopyramide:** This is a Class IA antiarrhythmic. It actually **prolongs** the PR interval and can worsen AV block due to its sodium channel blocking properties, making it contraindicated in this condition. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** For acute symptomatic bradycardia/AV block, **Atropine** is usually the initial drug [2], but **Isoprenaline** or **Adrenaline** infusions are preferred if Atropine fails or in cases of high-grade distal blocks [4]. * **Definitive Treatment:** The definitive management for chronic or high-grade AV block is a **Permanent Pacemaker**. * **Isoprenaline Side Effects:** It can cause palpitations, tremors, and may worsen myocardial ischemia by increasing oxygen demand [1].

Question 777: Which of the following drugs can cause pericarditis?

A. Procainamide, Methysergide, Amiodarone
B. Hydralazine, Procainamide, Amiodarone (Correct Answer)
C. Hydralazine, Methysergide, Amiodarone
D. Hydralazine, Methysergide

Explanation: The correct answer is **B: Hydralazine, Procainamide, Amiodarone.** ### **Explanation** The underlying medical concept here is **Drug-Induced Lupus Erythematosus (DILE)** and drug-induced fibrotic reactions. Pericarditis is a classic manifestation of DILE, which is most commonly associated with **Hydralazine** and **Procainamide**. 1. **Hydralazine and Procainamide:** These are the most notorious causes of DILE. They are metabolized via acetylation; "slow acetylators" are at a higher risk. The resulting autoimmune response frequently leads to pleuropericardial involvement (pericarditis and pleuritis). 2. **Amiodarone:** While primarily known for pulmonary fibrosis, Amiodarone can cause various "polyserositis" reactions, including pericarditis and pericardial effusion, as part of its systemic toxicity profile. ### **Analysis of Incorrect Options** * **Options A, C, and D (Methysergide):** Methysergide (an ergot alkaloid used for migraine prophylaxis) is famously associated with **retroperitoneal, endocardial, and pleuropulmonary fibrosis**. While it causes valvular thickening and restrictive cardiac disease, it is classically associated with *fibrosis* rather than acute *pericarditis*. Therefore, options containing Methysergide are less accurate in the context of this specific question. ### **NEET-PG High-Yield Pearls** * **DILE Mnemonic (SHIPP):** **S**ulfonamides, **H**ydralazine, **I**soniazid, **P**rocainamide, **P**henytoin. * **Antibodies:** In DILE, **Anti-histone antibodies** are positive in >95% of cases, while Anti-dsDNA (classic for SLE) is usually negative. * **Procainamide** has the highest risk (up to 20% of long-term users), while **Hydralazine** risk is dose-dependent (>200mg/day). * **Clinical Distinction:** Unlike idiopathic SLE, DILE rarely involves the CNS or Kidneys. Symptoms usually resolve upon drug discontinuation.

Question 778: What is the drug of choice in Hypertrophic Obstructive Cardiomyopathy (HOCM)?

A. Beta blocker (Correct Answer)
B. Dopamine
C. Amiodarone
D. ACE inhibitor

Explanation: ### Explanation **1. Why Beta Blockers are the Drug of Choice:** In Hypertrophic Obstructive Cardiomyopathy (HOCM), the primary pathology is a thickened interventricular septum that causes dynamic left ventricular outflow tract (LVOT) obstruction. **Beta blockers (e.g., Propranolol, Metoprolol)** are the first-line treatment because they are **negative inotropes** and **negative chronotropes**. * **Reduced Contractility:** By decreasing the force of contraction, they reduce the dynamic obstruction of the LVOT. * **Increased Diastolic Filling:** By slowing the heart rate, they increase the diastolic filling time (preload), which helps distend the left ventricle and move the septum away from the outflow tract, further reducing obstruction. **2. Why the Other Options are Incorrect:** * **Dopamine:** This is a positive inotrope. Increasing contractility in HOCM worsens the obstruction by narrowing the LVOT further. It is strictly contraindicated. * **Amiodarone:** While used to manage arrhythmias (like Atrial Fibrillation) associated with HOCM, it does not treat the underlying mechanical obstruction. * **ACE Inhibitors:** These are afterload reducers (vasodilators). Reducing systemic vascular resistance causes a drop in blood pressure, which triggers compensatory tachycardia and reduces ventricular volume, significantly worsening the LVOT gradient. **3. Clinical Pearls for NEET-PG:** * **Avoid the "3 Ds" in HOCM:** **D**igitalis (positive inotrope), **D**iuretics (reduce preload), and **D**ilators/Nitrates (reduce afterload). All three worsen the obstruction. * **Second-line drug:** If Beta blockers are contraindicated or ineffective, **Verapamil** (a non-dihydropyridine Calcium Channel Blocker) is the next choice. * **Goal of Therapy:** Maintain a "full, slow, and steady" heart to keep the LVOT open.

Question 779: In shock, what effect does dopamine, in renal doses, have on renal vasculature?

A. Reduction in peripheral resistance
B. Constriction of renal vasculature
C. Dilatation of renal vasculature (Correct Answer)
D. Increase in cardiac output

Explanation: **Explanation:** Dopamine is a unique catecholamine because its pharmacological effects are strictly **dose-dependent**. Understanding these dose ranges is a high-yield concept for NEET-PG. **1. Why the correct answer is right:** At **low doses (0.5–2 µg/kg/min)**, often referred to as the **"Renal Dose,"** dopamine selectively stimulates **D1 receptors** located in the renal, mesenteric, and coronary vascular beds. Activation of D1 receptors leads to an increase in intracellular cAMP, resulting in **vasodilation of the renal vasculature**. This increases renal blood flow and glomerular filtration rate (GFR), promoting diuresis and natriuresis. **2. Why the incorrect options are wrong:** * **Option A:** While dopamine can decrease total peripheral resistance at intermediate doses (via β2 stimulation), "renal dose" specifically targets D1 receptors for localized renal vasodilation, not systemic reduction in resistance. * **Option B:** Constriction occurs at **high doses (>10 µg/kg/min)** due to **α1 receptor** stimulation. This causes systemic vasoconstriction, which can actually decrease renal perfusion. * **Option D:** Increase in cardiac output is the primary effect of **intermediate doses (2–10 µg/kg/min)**, where **β1 receptor** stimulation increases myocardial contractility (inotropy) and heart rate (chronotropy). **NEET-PG High-Yield Pearls:** * **Dopamine Dose Summary:** Low (D1: Vasodilation) → Mid (β1: Inotropy) → High (α1: Vasoconstriction). * **Fenoldopam:** A selective D1 agonist used in hypertensive emergencies to maintain renal perfusion. * **Clinical Note:** Current guidelines (like SSC) suggest that "low-dose dopamine" does not significantly improve outcomes in acute renal failure compared to placebo, though it remains a classic pharmacological concept for exams.

Question 780: Beta blockers are indicated for all of the following conditions except?

A. Hypothyroidism (Correct Answer)
B. Alcohol withdrawal
C. Postural hypotension
D. Performance anxiety

Explanation: **Explanation** The correct answer is **Hypothyroidism**. Beta-blockers are contraindicated or ineffective here because the condition is characterized by a "hypometabolic" state with bradycardia and decreased sympathetic activity. Adding a beta-blocker would further worsen the bradycardia and potentially lead to heart block or failure. **Why the other options are incorrect:** * **Alcohol Withdrawal:** During withdrawal, there is massive sympathetic overactivity (tachycardia, tremors, hypertension). Beta-blockers (like Propranolol) are used as adjuncts to control these autonomic symptoms. * **Postural Hypotension:** This is a common **side effect** of many drugs, but beta-blockers are generally avoided or used with extreme caution in patients with orthostatic issues. However, in the context of this question, they are specifically **indicated for Hyperthyroidism** (not hypo), making Hypothyroidism the absolute "except" choice. * **Performance Anxiety:** Propranolol is the drug of choice for "stage fright." It blocks the peripheral manifestations of anxiety (palpitations and tremors) without causing sedation. **Clinical Pearls for NEET-PG:** 1. **Hyperthyroidism:** Beta-blockers (Propranolol) are the drug of choice for **Thyroid Storm**. They inhibit the peripheral conversion of T4 to T3 and control tachycardia. 2. **Pheochromocytoma:** Never give a beta-blocker alone; always give an **alpha-blocker first** to prevent a hypertensive crisis caused by unopposed alpha-receptor stimulation. 3. **Specific Beta-blockers:** * **Esmolol:** Shortest acting (used in hypertensive emergencies). * **Nebivolol:** Most cardioselective and produces Nitric Oxide (vasodilation). * **Carvedilol/Labetalol:** Combined alpha and beta-blocking activity.

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

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Drugs Used in Pulmonary Hypertension

Practice Questions

Drugs Used in Shock

Practice Questions

Cardiovascular Effects of Non-Cardiovascular Drugs

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