Cardiovascular Drugs Practice Questions

Q: Which drug decreases lipoprotein(a) in the blood?

Nicotinic acid (Niacin). ***Nicotinic acid (Niacin)*** - **Nicotinic acid**, particularly at higher doses, is known to significantly **reduce lipoprotein(a) [Lp(a)] levels** in the blood, although the exact mechanism is not fully understood. - This effect is clinically relevant because elevated Lp(a) is an **independent risk factor for cardiovascular disease**. *Statins* - **Statins** are potent inhibitors of **HMG-CoA reductase**, primarily known for reducing **LDL cholesterol** production. - While they are highly effective in lowering LDL-C, statins generally have **minimal or no effect on Lp(a)** levels, and some studies even suggest a potential slight increase. *Ezetimibe* - **Ezetimibe** works by inhibiting the absorption of **dietary and biliary cholesterol** in the small intestine via the **Niemann-Pick C1-Like 1 (NPC1L1) protein**. - Its primary effect is to **lower LDL cholesterol**, and it has **minimal to no impact on Lp(a) levels**. *CETP inhibitors* - **Cholesteryl ester transfer protein (CETP) inhibitors** (e.g., anacetrapib, evacetrapib) were developed to increase **HDL cholesterol** and decrease LDL cholesterol by inhibiting the transfer of cholesteryl esters from HDL to VLDL/LDL. - While they do affect lipoprotein metabolism significantly, they have been shown to have **inconsistent or modest effects on Lp(a)** levels, and their clinical use has been limited due to safety concerns or lack of clinical benefit.

Q: Which of the following changes in ECG is most commonly associated with Digitalis use?

Prolonged PR interval. ***Prolonged PR interval*** - Digitalis increases **parasympathetic tone** and slows **AV nodal conduction**, leading to a prolonged PR interval [1], [2]. - This effect is often an expected finding and may indicate therapeutic drug levels rather than toxicity, though significant prolongation can be a sign of overdose [1]. *Tall T waves* - **Tall, peaked T waves** are more commonly associated with **hyperkalemia**, a condition that can be exacerbated by digitalis toxicity but is not a direct ECG effect of digitalis itself [3]. - Digitalis typically causes **flattened or inverted T waves** as part of its characteristic "digitalis effect." *ST segment elevation* - **ST segment elevation** is a hallmark sign of **myocardial ischemia or infarction**, indicating acute coronary events. - While digitalis toxicity can cause arrhythmias, it does not directly lead to ST segment elevation. *Prolonged QT interval* - A **prolonged QT interval** is associated with an increased risk of **torsades de pointes** and is a common side effect of many antiarrhythmic drugs and electrolyte imbalances (e.g., hypokalemia, hypomagnesemia). - Digitalis typically causes **shortening of the QT interval** and can predispose to other forms of arrhythmias [1], [4].

Q: Patient with pulmonary fibrosis. Which antiarrhythmic drug is contraindicated?

Amiodarone. Amiodarone - **Amiodarone** is contraindicated in patients with pulmonary fibrosis due to its well-known and potentially severe pulmonary toxicity, which can exacerbate existing lung conditions or induce new ones like **interstitial lung disease**. Dose-related pulmonary toxicity is the most important adverse effect, and potentially fatal pulmonary fibrosis can be observed even at low doses [1]. - Its long half-life means that its toxic effects, including **pulmonary toxicity**, can persist for an extended period even after discontinuation [1], [2]. *Flecainide* - **Flecainide** is a Class IC antiarrhythmic drug primarily associated with cardiac side effects and is generally not contraindicated in patients with pulmonary fibrosis. - Its main risks include **proarrhythmia**, especially in patients with structural heart disease, but not pulmonary issues [3]. *IV ibutilide* - **IV ibutilide** is a Class III antiarrhythmic agent used for rapid conversion of atrial fibrillation/flutter and is not specifically contraindicated in pulmonary fibrosis. - Its primary concern is the risk of **QT prolongation** and **Torsades de Pointes**, rather than pulmonary complications. *Lidocaine* - **Lidocaine** is a Class IB antiarrhythmic typically used for ventricular arrhythmias, especially in the setting of acute myocardial infarction. It is not contraindicated in pulmonary fibrosis. - Its main side effects are **neurological (e.g., seizures, paresthesias)** at higher doses, not pulmonary complications.

Q: Which of the following drugs can be given in patients of primary pulmonary hypertension?

Bosentan. ***Bosentan*** - **Bosentan** is an **endothelin receptor antagonist** that blocks the vasoconstrictive and proliferative effects of endothelin-1, a key mediator in the pathogenesis of **pulmonary hypertension**. - It is an FDA-approved medication specifically used for the treatment of **pulmonary arterial hypertension (PAH)**, improving exercise capacity and delaying clinical worsening. *Icatibant* - **Icatibant** is a **bradykinin B2 receptor antagonist** used in the treatment of **hereditary angioedema**. - It has no known role or efficacy in the management of **primary pulmonary hypertension**. *Labetalol* - **Labetalol** is a **beta-blocker** with **alpha-1 adrenergic blocking activity** used primarily for systemic **hypertension** and **hypertensive emergencies**. - Beta-blockers are generally **contraindicated** in pulmonary hypertension as they can worsen right heart function and lead to clinical deterioration. *Sodium nitroprusside* - **Sodium nitroprusside** is a **direct arterial and venous vasodilator** used in hypertensive crises and severe heart failure by reducing both preload and afterload. - While it can lower systemic blood pressure, its use in pulmonary hypertension is **limited** due to the risk of **systemic hypotension** and the lack of selective pulmonary vasodilation compared to other agents.

Q: What type of drug is Sacubitril?

Neutral endopeptidase inhibitor. ***Neutral endopeptidase inhibitor*** - **Sacubitril** is specifically a **neprilysin inhibitor**, which is a type of neutral endopeptidase. - It works by preventing the breakdown of **natriuretic peptides**, leading to vasodilation and natriuresis, beneficial in heart failure. *ACE inhibitor* - **ACE inhibitors** block the conversion of angiotensin I to angiotensin II, leading to vasodilation and reduced aldosterone. - While sacubitril is often given in combination with an **angiotensin receptor blocker (valsartan)**, it is not an ACE inhibitor itself. *Calcium channel inhibitor* - **Calcium channel inhibitors** block the influx of calcium into vascular smooth muscle cells and cardiac myocytes, causing vasodilation and reduced myocardial contractility. - This is a distinct mechanism of action from sacubitril, which affects peptide degradation. *Beta adrenergic blocker* - **Beta-adrenergic blockers** inhibit the effects of catecholamines on beta-adrenergic receptors, reducing heart rate and myocardial contractility. - They are used in various cardiovascular conditions but operate through a different pathway than sacubitril.

Q: Niacin therapy is contraindicated in diabetes because it

Increases the blood sugar levels. ***Increases the blood sugar levels*** - **Niacin** can cause an increase in **insulin resistance** and glucose production, leading to elevated **blood sugar levels**. - This effect makes it contraindicated or used with extreme caution in patients with **diabetes mellitus**, as it can exacerbate **hyperglycemia**. *Causes scleroderma* - **Scleroderma** is a **chronic autoimmune** disorder characterized by widespread **fibrosis** and vascular dysfunction; it is not typically caused by niacin. - While niacin can have various side effects, **scleroderma** is not a known adverse reaction of this medication. *Difficult to give injection* - **Niacin** is available in various formulations, including **oral tablets** and **extended-release preparations**, which are easy to administer. - The mode of administration (injectable difficulty) is not a primary reason for its **contraindication in diabetes**. *Increases the metabolism of oral hypoglycemic drugs* - **Niacin** does not typically increase the **metabolism of oral hypoglycemic drugs**; rather, its primary concern in diabetes is its direct impact on **glucose metabolism**. - The interaction of niacin with **antidiabetic medications** is mainly related to its effect on **blood glucose levels**, requiring dose adjustments.

Q: What is the drug of choice for treating tachycardia induced by digitalis?

Phenytoin. ***Phenytoin*** - Phenytoin is the traditional drug of choice for **digitalis-induced tachyarrhythmias** as it blocks **sodium channels**, suppresses **automaticity**, and uniquely improves **AV conduction**. - It effectively counteracts digitalis toxicity by stabilizing the **cardiac membrane** and reducing **ectopic ventricular beats** without worsening conduction abnormalities. *Lidocaine* - Though lidocaine is a **Class IB antiarrhythmic** effective for ventricular arrhythmias, it was not the standard answer for this exam question context. - In modern practice, lidocaine may be preferred due to better **safety profile** and **IV availability**, but phenytoin remains the textbook answer for digitalis toxicity. *Reducing the dosage of digoxin* - While reducing digoxin dosage is important in **chronic management** of digitalis toxicity, it does not provide immediate relief from life-threatening arrhythmias. - This approach is too slow for acute situations requiring prompt **pharmacological intervention** to control dangerous tachycardia. *Verapamil* - Verapamil is **contraindicated** in digitalis toxicity as it can worsen **AV block** and exacerbate the **bradycardia** often associated with digitalis intoxication. - It can also increase **digoxin serum levels** by reducing renal clearance, potentially worsening the toxicity rather than treating it.

Q: Drugs acting on K+ channels include which of the following?

Nicorandil. ***Nicorandil*** - **Nicorandil** is a **potassium channel activator** that causes vasodilation by opening ATP-sensitive potassium channels in vascular smooth muscle cells. - This action leads to hyperpolarization of the cell membrane, making it more difficult for calcium influx and thus promoting relaxation and **vasodilation**. *Spironolactone* - **Spironolactone** is an **aldosterone antagonist** that works by blocking aldosterone receptors in the renal collecting tubules. - Its main effect is to increase sodium and water excretion while **conserving potassium**, making it a potassium-sparing diuretic, but it does not directly act on potassium channels for its primary mechanism. *Amiloride* - **Amiloride** is a **potassium-sparing diuretic** that directly inhibits **epithelial sodium channels (ENaC)** in the collecting duct. - By blocking sodium reabsorption, it indirectly reduces potassium secretion, thus conserving potassium, but it does not directly affect potassium channels. *Methyldopa* - **Methyldopa** is a **centrally acting alpha-2 adrenergic agonist** that reduces sympathetic outflow from the central nervous system. - It decreases peripheral vascular resistance and heart rate, leading to a reduction in blood pressure, and does not directly interact with potassium channels.

Q: Which drug is most classically associated with QT interval prolongation?

Quinidine. ***Quinidine*** - **Quinidine** is a Class IA antiarrhythmic drug that is the **classic textbook example** of drug-induced QT interval prolongation. - It blocks **sodium channels** and **potassium channels**, specifically delayed rectifier potassium channels (IKr). - This blockade of potassium channels **slows repolarization** of the cardiac myocyte, thereby prolonging the **QT interval** and increasing the risk of **Torsades de Pointes**. - Historically, quinidine has been the **prototype drug** used to teach this adverse effect in medical education. *Magnesium Sulfate* - **Magnesium sulfate** is used to **treat Torsades de Pointes**, a polymorphic ventricular tachycardia often associated with **QT prolongation**, but it does not primarily cause QT prolongation itself. - Its mechanism involves stabilizing the cardiac membrane and reducing abnormal electrical activity, rather than lengthening the **QT interval**. *Lignocaine* - **Lignocaine** (Lidocaine) is a Class IB antiarrhythmic drug that primarily blocks **sodium channels**, shortening the action potential duration in some cardiac tissues. - It does **not** significantly prolong the **QT interval**; in some cases, it can even shorten it, making it safer in patients with pre-existing QT prolongation. *Amiodarone* - **Amiodarone** is a Class III antiarrhythmic drug that blocks multiple channels, including **potassium channels**, leading to significant **QT interval prolongation**. - While amiodarone does prolong the QT interval considerably, the question asks for the **"most classically associated"** drug, which is quinidine—the historical prototype for this adverse effect. - The associated risk of **Torsades de Pointes** with amiodarone is lower than with Class IA agents like quinidine due to its **less proarrhythmic** profile, making quinidine the more classic teaching example.

Question 1

Which drug decreases lipoprotein(a) in the blood?

Accepted Answer

Nicotinic acid (Niacin)

Answer

Statins

Answer

Ezetimibe

Answer

CETP inhibitors

Question 2

Which of the following changes in ECG is most commonly associated with Digitalis use?

Accepted Answer

Prolonged PR interval

Answer

Tall T waves

Answer

ST segment elevation

Answer

Prolonged QT interval

Question 3

What is the primary mechanism of action of beta-blockers in the management of hypertension?

Accepted Answer

Decreasing heart rate and contractility to reduce cardiac output.

Answer

Direct relaxation of vascular smooth muscle.

Answer

Vasodilation through alpha-adrenergic blockade.

Answer

Inhibition of the renin-angiotensin-aldosterone system (RAAS).

Question 4

Patient with pulmonary fibrosis. Which antiarrhythmic drug is contraindicated?

Accepted Answer

Amiodarone

Answer

Flecainide

Answer

Lidocaine

Answer

IV ibutilide

Question 5

Which of the following drugs can be given in patients of primary pulmonary hypertension?

Accepted Answer

Bosentan

Answer

Icatibant

Answer

Sodium nitroprusside

Answer

Labetalol

Question 6

What type of drug is Sacubitril?

Accepted Answer

Neutral endopeptidase inhibitor

Answer

ACE inhibitor

Answer

Calcium channel inhibitor

Answer

Beta adrenergic blocker

Question 7

Niacin therapy is contraindicated in diabetes because it

Accepted Answer

Increases the blood sugar levels

Answer

Causes scleroderma

Answer

Difficult to give injection

Answer

Increases the metabolism of oral hypoglycemic drugs

Question 8

What is the drug of choice for treating tachycardia induced by digitalis?

Accepted Answer

Phenytoin

Answer

Lidocaine

Answer

Reducing the dosage of digoxin

Answer

Verapamil

Question 9

Drugs acting on K+ channels include which of the following?

Accepted Answer

Nicorandil

Answer

Methyldopa

Answer

Amiloride

Answer

Spironolactone

Question 10

Which drug is most classically associated with QT interval prolongation?

Accepted Answer

Quinidine

Answer

Magnesium Sulfate

Answer

Lignocaine

Answer

Amiodarone

Cardiovascular Drugs — MCQs

Cardiovascular Drugs — MCQs

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