Cardiovascular Drugs — MCQs

Cardiovascular Drugs Indian Medical PG Practice Questions and MCQs

Question 1121: The drug mainly causing afterload reduction is:

A. Captopril (Correct Answer)
B. Frusemide
C. Digoxin
D. Dobutamine

Explanation: ***Captopril*** - Captopril is an **ACE inhibitor** that blocks the conversion of angiotensin I to angiotensin II, leading to **vasodilation** of both arteries and veins. - This vasodilation primarily reduces **systemic vascular resistance (SVR)**, thereby decreasing the **afterload** on the heart. *Digoxin* - Digoxin is a **positive inotropic** drug that increases the force of myocardial contraction. - While it can improve cardiac output, its primary effect is not afterload reduction but rather enhancing **cardiac contractility** and slowing heart rate. *Frusemide* - Frusemide is a **loop diuretic** that works by inhibiting sodium and chloride reabsorption in the loop of Henle, leading to increased urinary output. - Its main effect is **preload reduction** (by decreasing blood volume), not directly reducing afterload. *Dobutamine* - Dobutamine is a **beta-1 adrenergic agonist** that primarily increases myocardial contractility and heart rate. - It is often used to improve cardiac output in conditions like **heart failure** through enhanced inotropy, rather than primarily reducing afterload.

Question 1122: What is the active principle of oleander?

A. Thevotoxin
B. Thevetin
C. Cerberin
D. Nerin (Correct Answer)

Explanation: Nerin (Neriin) - **Nerin** (also called neriin or neriine) is a **cardiac glycoside** that is a principal active compound in **common oleander** (*Nerium oleander*). - Ingestion causes severe **cardiac toxicity**, including arrhythmias, bradycardia, and heart block due to Na⁺/K⁺-ATPase inhibition [1]. - *Nerium oleander* contains multiple glycosides including neriine, oleandrin, and nerioside. Cerberin - **Cerberin** is a **cardiac glycoside** found in the **suicide tree** (*Cerbera manghas* or *Cerbera odollam*), not in oleander species. - While structurally similar and cardiotoxic, it is from a different plant genus. Thevetin - **Thevetin** (thevetin A and B) are cardiac glycosides primarily found in **yellow oleander** (*Thevetia peruviana*), not common oleander (*Nerium oleander*). - Though both are called "oleander," they are different species with different primary toxins. Thevotoxin - **Thevotoxin** is not a recognized or standard term for oleander toxins. - The confusion may arise from "thevetin," but this is primarily associated with *Thevetia* species, not *Nerium oleander*.

Question 1123: Which of the following drugs causes vasodilation primarily through direct effects on vascular smooth muscle?

A. Hydralazine (Correct Answer)
B. Aminophylline
C. Amrinone
D. Sildenafil

Explanation: ***Hydralazine*** - **Hydralazine** is a direct-acting **vasodilator** that primarily relaxes **arteriolar smooth muscle**, leading to decreased peripheral resistance and afterload. - Its exact mechanism of action is not fully understood, but it is thought to involve inhibition of **IP3-induced calcium release** from the sarcoplasmic reticulum. *Aminophylline* - **Aminophylline** is a methylxanthine derivative structurally similar to **theophylline**, primarily used as a bronchodilator. - Its vasodilatory effects are secondary to inhibition of **phosphodiesterase**, which increases cyclic adenosine monophosphate (cAMP) levels. *Amrinone* - **Amrinone** is a **phosphodiesterase-3 inhibitor** (PDE-3 inhibitor) that increases intracellular **cAMP** in cardiac myocytes and vascular smooth muscle cells. - This leads to both **positive inotropy** in the heart and **vasodilation** in blood vessels, but its primary action is not direct smooth muscle relaxation. *Sildenafil* - **Sildenafil** is a **phosphodiesterase-5 inhibitor** (PDE-5 inhibitor) primarily used for erectile dysfunction and pulmonary hypertension. - It works by preventing the degradation of **cGMP**, leading to relaxation of smooth muscle in specific vascular beds, not a general direct relaxation of all vascular smooth muscle typically associated with drugs like hydralazine.

Question 1124: Hypertension is associated with all of the following medications except:

A. Cyclosporine
B. NSAID
C. Erythropoietin
D. Levodopa (Correct Answer)

Explanation: ***Levodopa*** - **Levodopa** is a precursor to dopamine used in Parkinson's disease and is not directly associated with inducing or exacerbating hypertension. - While it can cause some cardiovascular side effects like **orthostatic hypotension**, it generally does not raise blood pressure. *Erythropoietin* - **Erythropoietin** can cause hypertension by increasing blood viscosity through elevated red blood cell mass and activating endothelin-1 leading to **vasoconstriction**. - It specifically increases the risk of **hypertensive crises** and can worsen pre-existing hypertension. *Cyclosporine* - **Cyclosporine** is an immunosuppressant that causes hypertension by inducing renal vasoconstriction, increasing sympathetic tone, and altering endothelial function. - It leads to **sodium and water retention** and directly impacts vascular resistance. *NSAID* - **Nonsteroidal anti-inflammatory drugs (NSAIDs)** can elevate blood pressure by inhibiting prostaglandin synthesis, which otherwise mediates vasodilation and natriuresis. - This inhibition can lead to **sodium and water retention** and increased systemic vascular resistance.

Question 1125: Which of the following drugs is not typically associated with an increased risk of ischemic stroke?

A. Cocaine
B. Oral contraceptives
C. Amphetamines
D. Barbiturates (Correct Answer)

Explanation: ***Barbiturates*** - While barbiturates can have various adverse effects due to central nervous system depression, they are **not typically associated with an increased risk of ischemic stroke**. - Their primary risks involve **respiratory depression, dependence, and overdose**, rather than thrombotic events. *Cocaine* - **Cocaine use is a significant risk factor for ischemic stroke**, particularly in younger individuals, by inducing vasoconstriction and promoting thrombus formation. - It can cause **acute hypertension**, **coronary vasospasm**, and cardiac arrhythmias, all contributing to stroke risk. *Oral contraceptives* - **Oral contraceptives, especially those with high estrogen doses**, can increase the risk of ischemic stroke by promoting a hypercoagulable state. - This risk is compounded in women who have **other risk factors** such as smoking, hypertension, or migraine with aura. *Amphetamines* - **Amphetamines are associated with an increased risk of ischemic stroke** due to their sympathomimetic effects, leading to vasoconstriction and elevated blood pressure. - They can also induce **vasculitis** and may contribute to clot formation.

Question 1126: Which of the following beta blockers is not considered cardioselective?

A. Atenolol
B. Esmolol
C. Metoprolol
D. Carvedilol (Correct Answer)

Explanation: ***Carvedilol*** - **Carvedilol** is a **non-selective beta-blocker** and also possesses **alpha-1 adrenergic blocking activity**, differentiating it from cardioselective agents. - Its mechanism of action involves blocking both **beta-1** and **beta-2 receptors**, as well as **alpha-1 receptors**, which contributes to its broader therapeutic uses, such as in heart failure. *Metoprolol* - **Metoprolol** is considered a **cardioselective (beta-1 selective) beta-blocker** at lower doses, primarily affecting the heart. - It has a lower propensity to cause **bronchoconstriction** or affect peripheral circulation compared to non-selective agents. *Atenolol* - **Atenolol** is a **cardioselective beta-blocker** that preferentially blocks **beta-1 adrenergic receptors** in the heart. - It is frequently used for conditions where specific **cardiac effects** are desired while minimizing impact on other systems. *Esmolol* - **Esmolol** is an **ultra-short-acting**, **cardioselective beta-blocker** that primarily blocks **beta-1 receptors**. - Its rapid onset and short duration of action make it particularly useful in **acute care settings**, such as perioperative hypertension or supraventricular tachyarrhythmias.

Question 1127: All are true regarding prazosin, except which of the following?

A. Selective alpha-1 blocker
B. Is an antihypertensive drug
C. Impaired glucose tolerance (Correct Answer)
D. First dose effect

Explanation: ***Impaired glucose tolerance*** - Prazosin, an **alpha-1-adrenergic blocker**, does not typically cause impaired glucose tolerance [1]. - Unlike **beta-blockers**, alpha-blockers generally have a neutral or even slightly beneficial effect on glucose metabolism [1]. *First dose effect* - This is a well-known side effect of prazosin, characterized by **marked hypotension** and **syncope** after the initial dose. - It occurs due to sudden **peripheral vasodilation** following alpha-1 blockade [1]. *Selective alpha-1 blocker* - Prazosin specifically and selectively blocks **alpha-1 adrenergic receptors**, leading to arterial and venous dilation [1]. - This selectivity differentiates it from non-selective alpha-blockers. *Is an antihypertensive drug* - Prazosin is indeed used as an **antihypertensive drug** due to its ability to reduce peripheral vascular resistance by blocking alpha-1 receptors on blood vessels [1]. - This action leads to a decrease in **blood pressure** [1].

Question 1128: For a patient on quinidine, select the most likely side effect to occur.

A. peripheral neuropathy
B. prolonged QT interval (Correct Answer)
C. bradycardia
D. action tremor

Explanation: ***prolonged QT interval*** - Quinidine is a **Class IA antiarrhythmic drug** that blocks sodium and potassium channels, leading to a significant **prolongation of the QT interval** on an electrocardiogram [1]. - This prolongation can increase the risk of **Torsades de Pointes**, a life-threatening polymorphic ventricular tachycardia [1]. *peripheral neuropathy* - **Peripheral neuropathy** is not a common or characteristic side effect associated with quinidine therapy. - Neuropathies are typically linked to drugs like **isoniazid** or certain **chemotherapeutic agents**. *bradycardia* - While quinidine can affect cardiac conduction, it's more commonly associated with **tachycardia** (due to anticholinergic effects) or arrhythmias rather than significant bradycardia [2]. - **Beta-blockers** and **calcium channel blockers** are more likely to cause symptomatic bradycardia. *action tremor* - **Action tremor** is generally not a recognized side effect of quinidine. - Tremors are often associated with other medications such as **lithium**, **valproic acid**, or **beta-agonists**.

Question 1129: Nitrates can be used for all of the following conditions except:

A. Esophageal spasm
B. Congestive heart failure
C. Renal colic
D. Cyanide poisoning (Correct Answer)

Explanation: ***Cyanide poisoning*** - This is the correct answer because **organic nitrates** (nitroglycerin, isosorbide dinitrate) used in cardiovascular practice are **not indicated** for cyanide poisoning. - While **nitrites** (amyl nitrite, sodium nitrite) - different compounds - can induce methemoglobinemia to bind cyanide, these are not the same as the organic nitrates used for cardiovascular conditions. - Current primary treatment for cyanide poisoning uses **hydroxocobalamin** and **sodium thiosulfate**, not cardiovascular nitrate preparations. *Congestive heart failure* - Nitrates cause **venodilation**, which reduces **preload** on the heart, thereby decreasing myocardial wall stress and oxygen demand. - This effect is beneficial in **acute decompensated heart failure** to manage symptoms like pulmonary congestion and dyspnea. - Commonly used preparations include IV nitroglycerin and sublingual nitroglycerin for acute management. *Esophageal spasm* - Nitrates relax **smooth muscle**, including the smooth muscle of the esophagus. - This property makes them useful in relieving the pain and discomfort associated with **diffuse esophageal spasm**. - Sublingual nitroglycerin can provide symptomatic relief. *Renal colic* - Nitrates cause **smooth muscle relaxation**, which can help to dilate the **ureters**. - This dilation can facilitate the passage of kidney stones and alleviate the severe pain associated with **renal colic**. - Though NSAIDs are first-line, nitrates may be used adjunctively for smooth muscle relaxation.

Question 1130: The choice of antihypertensive medication also depends upon the co-morbid illness of the patient, and all of the following recommendations have been made except:

A. In hypertensive patients with gout, diuretics are the first-line treatment. (Correct Answer)
B. In hypertensive patients with heart failure, ACE inhibitors may be preferred
C. In hypertensive patients with migraine, beta blockers are an excellent choice
D. In hypertensive patients with peripheral vascular disease, calcium channel blockers are recommended

Explanation: ***In hypertensive patients with gout, diuretics are the first-line treatment.*** * This statement is incorrect because **diuretics**, particularly **thiazide diuretics**, can **elevate uric acid levels** and precipitate or worsen gout attacks. * Therefore, they are generally **contraindicated or used with caution** in patients with gout, not recommended as first-line treatment. *In hypertensive patients with heart failure, ACE inhibitors may be preferred* * **ACE inhibitors** are a cornerstone of heart failure treatment due to their ability to **improve cardiac remodeling**, reduce mortality, and alleviate symptoms. * They are often preferred for their **vasodilatory effects** and ability to prevent volume overload, which benefits patients with heart failure. *In hypertensive patients with migraine, beta blockers are an excellent choice* * **Beta-blockers**, such as propranolol, are effective in both **blood pressure control** and the **prophylaxis of migraines** [1]. * This makes them an excellent choice for a hypertensive patient who also suffers from migraines, offering a dual therapeutic benefit [1]. *In hypertensive patients with peripheral vascular disease, calcium channel blockers are recommended* * **Calcium channel blockers (CCBs)**, especially dihydropyridines like amlodipine, are beneficial in peripheral vascular disease (PVD) due to their **vasodilatory effects**. * They can **improve blood flow** to the extremities, which is crucial in PVD, without negatively impacting symptoms like claudication.

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

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