Cardiovascular Drugs Practice Questions

Q: Atorvastatin is used as an anti-dyslipidemic drug. These drugs inhibit their target enzyme by:-

Competitive inhibition. ***Competitive inhibition*** - Atorvastatin is a **statin**, which acts as a **competitive inhibitor** of **HMG-CoA reductase**, the rate-limiting enzyme in cholesterol synthesis. - It competes with the natural substrate, HMG-CoA, for binding to the **active site of the enzyme**, thereby reducing cholesterol production. *Uncompetitive* - **Uncompetitive inhibitors** bind only to the **enzyme-substrate complex**, not to the free enzyme. - This type of inhibition is characterized by a decrease in both **apparent Vmax** and **apparent Km**. *Noncompetitive inhibition* - **Noncompetitive inhibitors** bind to an allosteric site on the enzyme, distinct from the active site, and can bind to either the **free enzyme or the enzyme-substrate complex**. - This leads to a decrease in the **apparent Vmax** but does not affect Km. *Irreversible inhibition* - **Irreversible inhibitors** form a **strong covalent bond** with the enzyme, permanently inactivating it. - Statins do not form covalent bonds with HMG-CoA reductase; their inhibition is **reversible** upon drug discontinuation.

Q: Which of the following drug causes postural hypotension commonly?

Alpha blocker. ***Alpha blocker*** - **Alpha-1 adrenergic blockers** cause common postural hypotension by blocking **alpha-1 receptors** on vascular smooth muscle, leading to vasodilation and reduced peripheral vascular resistance. - This vasodilation, especially in the upright position, can cause blood to pool in the lower extremities, decreasing venous return to the heart and thus lowering blood pressure. *Angiotensin receptor blockers* - These drugs block the effects of **angiotensin II**, leading to vasodilation and decreased aldosterone secretion, typically causing a more gradual and less pronounced drop in blood pressure. - While they can cause hypotension, **postural hypotension** is less common and usually less severe compared to alpha blockers due to their different mechanism of action and less abrupt vasodilation. *Beta blocker* - **Beta-blockers** primarily reduce heart rate and myocardial contractility, thereby decreasing cardiac output, which can contribute to generalized hypotension. - They do not directly cause significant **vasodilation** in the same manner as alpha-blockers, making postural hypotension less common unless there are other contributing factors. *ACE inhibitor* - **ACE inhibitors** prevent the conversion of angiotensin I to **angiotensin II**, leading to vasodilation and reduced aldosterone. - They can cause hypotension, especially with the first dose or in volume-depleted patients, but **postural hypotension** is typically less frequent and severe than with alpha-blockers.

Q: The drug that causes fall in elderly patients with postural hypotension is:-

Prazosin. ***Prazosin*** - **Alpha-1 adrenergic blocker** used to treat hypertension and benign prostatic hyperplasia (BPH) - Commonly causes **orthostatic hypotension (postural hypotension)** as a side effect by blocking alpha-1 receptors on vascular smooth muscle, preventing compensatory vasoconstriction upon standing - Leads to **dizziness, lightheadedness, and falls**, especially in elderly patients who have reduced baroreceptor sensitivity - **First-dose phenomenon** is particularly notable, with marked hypotension after the initial dose *Acarbose* - Alpha-glucosidase inhibitor used to treat type 2 diabetes by reducing carbohydrate absorption in the intestine - Primary side effects are **gastrointestinal** (flatulence, diarrhea, abdominal discomfort) - Does not affect blood pressure or cause postural hypotension *Nor-adrenaline (Norepinephrine)* - **Vasopressor** and sympathomimetic agent that causes vasoconstriction through alpha-adrenergic receptor stimulation - **Increases blood pressure** and is used to treat severe hypotension in critical care settings - Would not cause falls due to postural hypotension; rather, it counteracts hypotension *Metformin* - **Biguanide** oral hypoglycemic agent for type 2 diabetes that primarily decreases hepatic glucose production and increases insulin sensitivity - Main side effects include gastrointestinal disturbances and rare lactic acidosis - Not associated with postural hypotension or increased risk of falls

Q: Which of the following is a direct renin inhibitor?

Aliskiren. ***Aliskiren*** - **Aliskiren** directly inhibits **renin**, the enzyme responsible for initiating the **renin-angiotensin-aldosterone system (RAAS)**, by preventing the conversion of **angiotensinogen to angiotensin I**. - This mechanism of action is distinct from other RAAS inhibitors that act further down the pathway. *Perindopril* - **Perindopril** is an **ACE inhibitor**, which works by blocking the enzyme that converts **angiotensin I to angiotensin II**. - It does not directly inhibit **renin** activity. *Losartan* - **Losartan** is an **angiotensin receptor blocker (ARB)**, which works by preventing **angiotensin II** from binding to its receptors. - It does not directly inhibit **renin** and primarily acts by blocking the effects of already formed **angiotensin II**. *Vernakalant* - **Vernakalant** is an antiarrhythmic drug primarily used for the acute conversion of **atrial fibrillation**. - It works by blocking specific **potassium and sodium channels** in the atria, and has no direct activity on the **renin-angiotensin-aldosterone system**.

Q: Drug of choice in cardiogenic shock is

Dopamine. ***Dopamine*** - **Dopamine** is often considered the **drug of choice** in cardiogenic shock because, at low to moderate doses, it increases myocardial contractility and heart rate (positive inotropic and chronotropic effects) while also improving renal perfusion. - Its ability to stimulate **alpha-1, beta-1, and dopaminergic receptors** makes it effective in improving cardiac output and maintaining organ perfusion in this critical condition. *Phenylephrine* - **Phenylephrine** is a selective **alpha-1 adrenergic agonist** that causes potent vasoconstriction and increases systemic vascular resistance. - While it effectively raises blood pressure, it **lacks inotropic effects** and can actually **reduce cardiac output** through reflex bradycardia and increased afterload. - Its strong vasoconstrictive effects without inotropic support make it **not suitable** as a primary agent in cardiogenic shock where cardiac contractility is already compromised. *Noradrenaline* - **Noradrenaline (norepinephrine)** is a potent vasoconstrictor primarily acting on alpha-1 receptors, leading to a significant increase in systemic vascular resistance and blood pressure. - While useful in some forms of shock, its strong vasoconstrictive effect can **increase afterload** and potentially worsen myocardial oxygen demand in cardiogenic shock with already compromised cardiac function. *Adrenaline* - **Adrenaline (epinephrine)** has strong **beta-1 and alpha-1 agonist effects**, leading to increased heart rate, contractility, and vasoconstriction. - While it can improve blood pressure and cardiac output, its significant **chronotropic and arrhythmogenic effects**, along with increased myocardial oxygen demand, make it less favorable than dopamine as a first-line agent in cardiogenic shock.

Q: Which of the following drugs decreases plasma renin activity

Clonidine. ***Clonidine*** - **Clonidine** is a centrally acting alpha-2 adrenergic agonist that reduces **sympathetic outflow** from the brainstem. - This reduction in sympathetic activity leads to decreased release of **norepinephrine**, which in turn reduces renin secretion by the kidneys. *Nifedipine* - **Nifedipine** is a **dihydropyridine calcium channel blocker** that causes peripheral vasodilation. - The vasodilation often leads to a **reflex increase in sympathetic activity** and, consequently, an increase in plasma renin activity. *Hydralazine* - **Hydralazine** is a direct systemic **vasodilator** that decreases peripheral vascular resistance. - This vasodilation can cause a **reflex increase in sympathetic activity** and **renin release** as the body tries to compensate for the drop in blood pressure. *Enalapril* - **Enalapril** is an **ACE inhibitor** that blocks the conversion of angiotensin I to angiotensin II. - This action directly leads to **increased plasma renin activity** due to the disruption of the negative feedback loop on renin release.

Q: Plasma Renin activity is lowered by which of the following group of drugs?

Alpha 2 agonists. ***Alpha 2 agonists*** - **Alpha-2 agonists** (e.g., clonidine) work by stimulating central alpha-2 adrenergic receptors, which reduces **sympathetic outflow** from the CNS. - This reduction in sympathetic tone decreases **renin release** from the juxtaglomerular cells in the kidney, thereby lowering plasma renin activity. *Arteriolar dilators* - **Arteriolar dilators** (e.g., hydralazine, minoxidil) decrease peripheral vascular resistance and lower blood pressure. - This reduction in blood pressure and renal perfusion can activate the **renin-angiotensin-aldosterone system (RAAS)**, leading to an **increase** in plasma renin activity as a compensatory mechanism. *Calcium channel blockers* - **Calcium channel blockers** (e.g., nifedipine, amlodipine) directly relax vascular smooth muscle and reduce peripheral resistance. - Some calcium channel blockers, particularly **dihydropyridines**, can cause reflex sympathetic activation due to vasodilation, potentially **increasing** renin release. *ACE inhibitors* - **ACE inhibitors** (e.g., enalapril, lisinopril) block the conversion of angiotensin I to angiotensin II. - By inhibiting the negative feedback that angiotensin II typically exerts on renin release, ACE inhibitors actually lead to an **increase** in plasma renin activity.

Q: Drug used for euvolemic hyponatremia in patient with advanced congestive heart failure is?

Tolvaptan. ***Tolvaptan*** - **Tolvaptan** is a selective **vasopressin V2-receptor antagonist** that promotes free water excretion (aquaresis) without significantly altering electrolyte balance, making it suitable for euvolemic hyponatremia [1]. - It works by blocking the action of **antidiuretic hormone (ADH)**, which is often elevated in patients with **congestive heart failure (CHF)** leading to water retention and hyponatremia [2]. *Nesiritide* - **Nesiritide** is a **recombinant human B-type natriuretic peptide (BNP)** that causes vasodilation and diuresis, but it is primarily used for acutely decompensated heart failure with signs of congestion, not specifically for euvolemic hyponatremia [1]. - While it can induce diuresis, its main role is to reduce **preload** and **afterload**, and it does not directly target the mechanism of euvolemic hyponatremia as effectively as an aquaretic agent [1]. *Metoprolol* - **Metoprolol** is a **beta-blocker** used to reduce heart rate and blood pressure, improving cardiac function in CHF patients. - It does not directly address **hyponatremia** and its mechanism of action is unrelated to water balance or sodium concentration. *Hydrocortisone* - **Hydrocortisone** is a **corticosteroid** used for conditions like adrenal insufficiency, inflammation, or allergic reactions. - It has no direct role in the management of **hyponatremia** or **congestive heart failure**.

Q: The drug that can cause hirsutism is

Minoxidil. ***Minoxidil*** - **Minoxidil** is a potent **vasodilator** that can cause **hirsutism** as a common side effect, especially when used orally. - Due to its hair growth stimulating effect, it is also topically used to treat **androgenetic alopecia** [1]. *Dactinomycin* - **Dactinomycin** is an **antineoplastic antibiotic** primarily used in cancer chemotherapy. - Its main side effects include **myelosuppression**, nausea, vomiting, and mucositis, not hirsutism. *Cycloserine* - **Cycloserine** is an antibiotic mainly used to treat **tuberculosis** [2]. - Its adverse effects are predominantly **neurological** and psychiatric, such as seizures and psychosis, not affecting hair growth [2]. *Valsartan* - **Valsartan** is an **angiotensin receptor blocker (ARB)** used to treat hypertension and heart failure. - Common side effects include dizziness and hyperkalemia; it does not cause hirsutism.

Q: A drug used to prevent niacin-induced flushing is

Aspirin. ***Aspirin*** - Niacin-induced flushing is mediated by **prostaglandins**, primarily prostaglandin D2 (PGD2), which cause vasodilation. - **Aspirin**, being a non-steroidal anti-inflammatory drug (NSAID) and a cyclooxygenase (COX) inhibitor, blocks the synthesis of prostaglandins, thereby reducing flushing. *Cetirizine* - Cetirizine is a **second-generation H1 antihistamine** primarily used to treat allergic symptoms like rhinitis or urticaria. - It does not significantly affect prostaglandin pathways implicated in niacin-induced flushing. *Dexamethasone* - Dexamethasone is a **corticosteroid** with potent anti-inflammatory and immunosuppressive effects. - While it can broadly reduce inflammation, it is not the primary or most appropriate treatment for niacin-induced flushing, which is better managed with prostaglandin inhibitors. *Paracetamol* - Paracetamol (acetaminophen) is an **analgesic and antipyretic** that works primarily by inhibiting prostaglandin synthesis in the central nervous system. - It has minimal anti-inflammatory effects and does not effectively reduce peripheral prostaglandin production responsible for niacin flush.

Question 1

Atorvastatin is used as an anti-dyslipidemic drug. These drugs inhibit their target enzyme by:-

Accepted Answer

Competitive inhibition

Answer

Noncompetitive inhibition

Answer

Irreversible inhibition

Answer

Uncompetitive inhibition

Question 2

Which of the following drug causes postural hypotension commonly?

Accepted Answer

Alpha blocker

Answer

Angiotensin receptor blockers

Answer

Beta blocker

Answer

ACE inhibitor

Question 3

The drug that causes fall in elderly patients with postural hypotension is:-

Accepted Answer

Prazosin

Answer

Acarbose

Answer

Nor-adrenaline

Answer

Metformin

Question 4

Which of the following is a direct renin inhibitor?

Accepted Answer

Aliskiren

Answer

Perindopril

Answer

Losartan

Answer

Vernakalant

Question 5

Drug of choice in cardiogenic shock is

Accepted Answer

Dopamine

Answer

Noradrenaline

Answer

Adrenaline

Answer

Phenylephrine

Question 6

Which of the following drugs decreases plasma renin activity

Accepted Answer

Clonidine

Answer

Nifedipine

Answer

Hydralazine

Answer

Enalapril

Question 7

Plasma Renin activity is lowered by which of the following group of drugs?

Accepted Answer

Alpha 2 agonists

Answer

Arteriolar dilators

Answer

Calcium channel blockers

Answer

ACE inhibitors

Question 8

Drug used for euvolemic hyponatremia in patient with advanced congestive heart failure is?

Accepted Answer

Tolvaptan

Answer

Nesiritide

Answer

Metoprolol

Answer

Hydrocortisone

Question 9

The drug that can cause hirsutism is

Accepted Answer

Minoxidil

Answer

Dactinomycin

Answer

Cycloserine

Answer

Valsartan

Question 10

A drug used to prevent niacin-induced flushing is

Accepted Answer

Aspirin

Answer

Dexamethasone

Answer

Paracetamol

Answer

Cetirizine

Cardiovascular Drugs — MCQs

Cardiovascular Drugs — MCQs

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