Cardiovascular Drugs Practice Questions

Q: Lipid-lowering agents, statins, act in all the following ways except:

Decreased LDL receptors. ### Explanation Statins (HMG-CoA reductase inhibitors) are the first-line agents for hypercholesterolemia. The core mechanism involves the competitive inhibition of the rate-limiting enzyme in cholesterol biosynthesis. **Why "Decreased LDL receptors" is the correct answer (the exception):** Statins actually **increase** the expression of LDL receptors. When statins inhibit hepatic cholesterol synthesis, the intracellular pool of cholesterol drops. To compensate, the liver upregulates the synthesis of LDL receptors on the hepatocyte surface. These receptors then clear more LDL and VLDL remnants from the circulation, leading to a significant drop in plasma LDL levels. Therefore, saying statins *decrease* these receptors is physiologically incorrect. **Analysis of Incorrect Options:** * **A & C (Inhibiting HMG CoA reductase / Decreased hepatic synthesis):** These are the primary actions of statins. By mimicking the substrate HMG-CoA, they block the conversion of HMG-CoA to mevalonate, directly halting endogenous cholesterol production. * **D (Decreasing VLDL):** Since VLDL is a precursor to LDL and requires cholesterol for its assembly, the reduction in hepatic cholesterol availability leads to a secondary decrease in VLDL secretion. **High-Yield Clinical Pearls for NEET-PG:** * **Pleiotropic Effects:** Statins have "extra" benefits beyond lipid lowering, including plaque stabilization, anti-inflammatory properties, and improved endothelial function. * **Timing:** Most statins (except Atorvastatin and Rosuvastatin) should be taken at **bedtime** because peak cholesterol synthesis occurs during the night. * **Side Effects:** Monitor for **myopathy** (elevated CPK) and hepatotoxicity. Risk increases when combined with Fibrates or Cytochrome P450 inhibitors. * **Contraindication:** Statins are strictly **Teratogenic** (Category X).

Q: Which of the following is FALSE regarding quinidine?

Used in hypertension. **Explanation:** Quinidine is a **Class IA antiarrhythmic** drug derived from the cinchona bark. The correct answer is **B** because Quinidine is not used in the treatment of hypertension; in fact, it can cause hypotension as a side effect due to its alpha-adrenergic blocking properties. **Analysis of Options:** * **A. Increases effective refractory period (ERP):** This is **TRUE**. As a Class IA agent, Quinidine blocks fast sodium channels and inhibits outward potassium channels. Blocking potassium channels prolongs the action potential duration (APD) and the ERP. * **B. Used in hypertension:** This is **FALSE**. It has no role in managing high blood pressure. Its primary use is maintaining sinus rhythm in patients with atrial flutter or fibrillation. * **C. Causes paradoxical tachycardia:** This is **TRUE**. Quinidine has significant **antimuscarinic (atropine-like) effects**. In atrial flutter, it can enhance AV conduction, leading to a dangerous increase in ventricular rate (paradoxical tachycardia). To prevent this, it is usually co-administered with AV nodal blockers like Digoxin or Beta-blockers. * **D. Cinchonism is seen:** This is **TRUE**. Cinchonism is a classic adverse effect profile characterized by tinnitus, blurred vision, dizziness, and headache. **High-Yield Clinical Pearls for NEET-PG:** * **ECG Changes:** Quinidine causes prolongation of the **QT interval**. * **Torsades de Pointes:** Due to QT prolongation, it can trigger this life-threatening polymorphic ventricular tachycardia. * **Drug Interaction:** Quinidine increases plasma levels of **Digoxin** by displacing it from tissue binding sites and reducing its renal clearance. * **Hematology:** It is a well-known cause of immune-mediated thrombocytopenia.

Q: Which hypolipidemic drug can exacerbate the symptoms of gout?

Niacin. **Explanation:** **Niacin (Nicotinic Acid)** is the correct answer because it competes with uric acid for the same organic acid secretory carrier in the proximal convoluted tubules of the kidney. This competition leads to decreased renal excretion of uric acid, resulting in **hyperuricemia**. In susceptible individuals, this elevated serum uric acid can precipitate an acute attack of **gout**. **Analysis of Options:** * **Ezetimibe (A):** A cholesterol absorption inhibitor that acts on the NPC1L1 transporter in the intestine. It does not affect renal tubular secretion or uric acid levels. * **Gemfibrozil (B):** A Fibrate that activates PPAR-α. While fibrates can occasionally cause muscle toxicity, they do not typically cause hyperuricemia. In fact, Fenofibrate (another fibrate) actually has a mild uricosuric effect (lowers uric acid). * **Simvastatin (D):** An HMG-CoA reductase inhibitor. The primary side effects of statins are hepatotoxicity and myopathy (rhabdomyolysis); they do not interfere with uric acid metabolism. **NEET-PG High-Yield Pearls:** * **Niacin Side Effects:** The most common side effect is **cutaneous flushing** (mediated by Prostaglandin $D_2$ and $E_2$; prevented by Aspirin). The most serious side effects are **hepatotoxicity** and **hyperglycemia** (caution in diabetics). * **Clinical Contraindications:** Niacin should be avoided in patients with active peptic ulcer disease, gout, and uncontrolled diabetes. * **Lipid Profile:** Niacin is the most effective drug for **increasing HDL levels** and is also useful for lowering Triglycerides and LDL.

Q: Which drug is primarily used for the treatment of hypertriglyceridemia?

Gemfibrozil. **Explanation:** **Gemfibrozil** is the correct answer because it belongs to the **Fibrates** class of drugs, which are the first-line agents for treating isolated hypertriglyceridemia. **Mechanism of Action:** Fibrates act as agonists at the **PPAR-α (Peroxisome Proliferator-Activated Receptor-alpha)** receptors. Activation of these receptors increases the expression of **Lipoprotein Lipase (LPL)**, which enhances the clearance of triglyceride-rich lipoproteins (VLDL and chylomicrons). They also decrease the hepatic synthesis of VLDL. **Analysis of Incorrect Options:** * **Cholestyramine & Resins (Options A & D):** These are Bile Acid Sequestrants. They primarily lower LDL cholesterol by preventing bile acid reabsorption. Crucially, they can actually **increase triglyceride levels** in some patients; therefore, they are contraindicated in severe hypertriglyceridemia. * **Nicotinic Acid (Option B):** While Niacin can lower triglycerides and raise HDL, it is no longer a first-line treatment due to its side effect profile (flushing, glucose intolerance, hyperuricemia) and is generally reserved for refractory cases. **High-Yield NEET-PG Pearls:** * **Drug of Choice:** Fibrates (e.g., Gemfibrozil, Fenofibrate) are the drugs of choice when triglycerides are >500 mg/dL to prevent **acute pancreatitis**. * **Drug Interaction:** Combining Gemfibrozil with Statins significantly increases the risk of **myopathy and rhabdomyolysis** because Gemfibrozil inhibits the glucuronidation (metabolism) of statins. * **Fenofibrate** is preferred over Gemfibrozil if a statin-fibrate combination is necessary, as it has a lower risk of causing myopathy.

Q: Which prostacyclin agonist is usually given orally?

Selexipag. **Explanation:** **Selexipag** is the correct answer because it is a selective, non-prostanoid **prostacyclin (IP) receptor agonist** specifically designed for **oral administration**. Unlike traditional prostacyclin analogs, Selexipag is a prodrug metabolized into its active form (ACT-333602), providing a longer half-life and making it suitable for twice-daily oral dosing in the management of Pulmonary Arterial Hypertension (PAH). **Analysis of Incorrect Options:** * **Iloprost:** This is a synthetic analog of PGI2. While it can be given intravenously, it is most commonly administered via **inhalation** (6–9 times daily) due to its very short half-life. * **Treprostinil (often confused with 'Teleprost'):** While Treprostinil has an oral formulation (Orenitram), it is more famously known for its subcutaneous or intravenous infusion and inhalation. (Note: "Teleprost" is likely a distractor or misspelling of Treprostinil). * **Riociguat:** This drug is used for PAH, but it is **not a prostacyclin agonist**. It is a **Soluble Guanylate Cyclase (sGC) stimulator** that works via the Nitric Oxide pathway. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Selexipag targets the IP receptor, leading to vasodilation and anti-proliferative effects on pulmonary vessels. * **PAH Treatment Hierarchy:** Oral agents like Selexipag or Endothelin receptor antagonists (Bosentan/Ambrisentan) are preferred for early-stage PAH (WHO Class II/III), whereas IV Epoprostenol remains the gold standard for severe, late-stage disease (Class IV). * **Side Effects:** Common to all prostacyclin pathways—headache, jaw pain, diarrhea, and flushing.

Q: A patient is prescribed a drug for treating hypertension that can cause tachycardia and marked fluid retention. Which of the following could be the prescribed drug?

Minoxidil. **Explanation:** The correct answer is **Minoxidil**. **Mechanism and Rationale:** Minoxidil is a potent **direct-acting peripheral vasodilator** that works by opening ATP-sensitive potassium channels in vascular smooth muscle, leading to hyperpolarization and relaxation of arterioles. This profound vasodilation significantly drops peripheral resistance, triggering two major compensatory homeostatic mechanisms: 1. **Reflex Tachycardia:** The drop in blood pressure activates the baroreceptor reflex, leading to increased sympathetic outflow. 2. **Fluid Retention:** Reduced renal perfusion and sympathetic activation trigger the Renin-Angiotensin-Aldosterone System (RAAS), causing significant sodium and water retention. To counteract these side effects, Minoxidil is almost always co-administered with a **beta-blocker** (to control heart rate) and a **loop diuretic** (to manage edema). **Analysis of Incorrect Options:** * **A. Captopril:** An ACE inhibitor. It typically causes a slight decrease in sympathetic activity and promotes sodium excretion (natriuresis), making it unlikely to cause tachycardia or fluid retention. * **B. Guanethidine:** An adrenergic neuron blocker. It prevents the release of norepinephrine, typically causing bradycardia and orthostatic hypotension, not tachycardia. * **D. Metoprolol:** A cardioselective beta-1 blocker. It decreases heart rate (bradycardia) and is used to treat tachycardia, not cause it. **NEET-PG High-Yield Pearls:** * **Hypertrichosis:** Minoxidil causes abnormal hair growth; it is used topically for androgenetic alopecia. * **Hydralazine:** Another direct vasodilator that causes similar reflex tachycardia and a lupus-like syndrome (slow acetylators). * **Clinical Use:** Minoxidil is reserved for **refractory hypertension** that does not respond to multidrug regimens.

Q: Aspirin is used in the prophylaxis of myocardial infarction because it results in:

Inhibition of cyclooxygenase. ### Explanation **Correct Answer: B. Inhibition of cyclooxygenase** **Mechanism of Action:** Aspirin (Acetylsalicylic acid) is the only NSAID that **irreversibly** inhibits the enzyme **Cyclooxygenase-1 (COX-1)** by acetylating a specific serine residue. In platelets, COX-1 is responsible for converting arachidonic acid into **Thromboxane A2 (TXA2)**, a potent vasoconstrictor and platelet aggregator. Since platelets are anuclear and cannot synthesize new enzymes, the inhibition lasts for the entire lifespan of the platelet (approx. 7–10 days). This reduction in TXA2 shifts the balance toward Prostacyclin (PGI2), preventing thrombus formation in coronary arteries. **Analysis of Incorrect Options:** * **A. Inhibition of thromboxane synthetase:** Aspirin inhibits the *upstream* enzyme COX-1, not thromboxane synthetase. Specific thromboxane synthetase inhibitors (e.g., Dazoxiben) exist but are not the mechanism for aspirin. * **C. Decreased serum lipids:** Aspirin has no significant effect on lipid profiles. Statins are the primary class used for lipid-lowering in MI prophylaxis. * **D. Coronary steal phenomenon:** This occurs when a vasodilator (like Dipyridamole or Hydralazine) dilates healthy vessels, "stealing" blood away from ischemic areas. Aspirin does not cause this. **High-Yield Clinical Pearls for NEET-PG:** * **Low-dose Aspirin (75–150 mg):** Highly selective for COX-1 (anti-platelet effect). * **High-dose Aspirin:** Inhibits both COX-1 and COX-2 (analgesic/anti-inflammatory effect). * **Primary Prophylaxis:** Aspirin is used to prevent the first MI in high-risk patients. * **Secondary Prophylaxis:** Used in patients with a history of MI or stroke to prevent recurrence. * **Side Effect:** Gastric irritation and bleeding (due to inhibition of protective PGE2 in the stomach).

Q: Acanthosis nigricans can be caused by which drug?

Nicotinic acid. **Explanation:** Nicotinic acid (Niacin), used in the treatment of dyslipidemia, is a well-known pharmacological cause of **Acanthosis Nigricans (AN)**. The underlying mechanism involves the drug’s ability to induce insulin resistance [1] and increase the expression of **Epidermal Growth Factor Receptors (EGFR)** on keratinocytes. This leads to the characteristic hyperpigmented, velvety plaques typically found in intertriginous areas like the axilla and neck. **Analysis of Options:** * **Nicotinic acid (Correct):** High doses of Niacin can trigger AN. Other common side effects include cutaneous flushing (mediated by prostaglandins) and hyperuricemia. * **Amphotericin-B:** This antifungal is notorious for its nephrotoxicity and infusion-related reactions ("shake and bake" symptoms), but it does not cause AN. * **Ketoconazole:** An antifungal known for inhibiting steroid synthesis, leading to gynecomastia and decreased libido. It is also associated with hepatotoxicity. * **Nalidixic acid:** A quinolone antibiotic primarily associated with photosensitivity reactions and intracranial hypertension (pseudotumor cerebri) in children. **High-Yield Clinical Pearls for NEET-PG:** * **Drug-induced AN:** Other culprits include systemic glucocorticoids, oral contraceptives, and growth hormone therapy. * **Malignant AN:** If AN appears suddenly and is extensive (especially involving the palms/tripe palms), it is often a paraneoplastic sign of **Gastric Adenocarcinoma**. * **Niacin Flushing:** This can be mitigated by pre-treating with **Aspirin**, which inhibits the prostaglandin-mediated vasodilation.

Question 1

Which of the following drugs can cause coronary steal phenomenon?

Accepted Answer

Hydralazine

Answer

Glyceryl trinitrate

Answer

Disopyramide

Answer

Diltiazem

Question 2

Lipid-lowering agents, statins, act in all the following ways except:

Accepted Answer

Decreased LDL receptors

Answer

Decreased hepatic cholesterol synthesis

Answer

Inhibiting HMG CoA reductase

Answer

Decreasing VLDL

Question 3

Which of the following is FALSE regarding quinidine?

Accepted Answer

Used in hypertension

Answer

It increases effective refractory period

Answer

Causes paradoxical tachycardia

Answer

Cinchonism is seen

Question 4

Which hypolipidemic drug can exacerbate the symptoms of gout?

Accepted Answer

Niacin

Answer

Ezetimibe

Answer

Gemfibrozil

Answer

Simvastatin

Question 5

Which drug is primarily used for the treatment of hypertriglyceridemia?

Accepted Answer

Gemfibrozil

Answer

Cholestyramine

Answer

Nicotinic acid

Answer

Resins

Question 6

Long-term ACE inhibitor therapy may retard the progression of which of the following conditions?

Accepted Answer

All of the above

Answer

Diabetic retinopathy

Answer

Hypertensive nephropathy

Answer

Diabetic nephropathy

Question 7

Which prostacyclin agonist is usually given orally?

Accepted Answer

Selexipag

Answer

Teleprost

Answer

Iloprost

Answer

Riociguat

Question 8

A patient is prescribed a drug for treating hypertension that can cause tachycardia and marked fluid retention. Which of the following could be the prescribed drug?

Accepted Answer

Minoxidil

Answer

Captopril

Answer

Guanethidine

Answer

Metoprolol

Question 9

Aspirin is used in the prophylaxis of myocardial infarction because it results in:

Accepted Answer

Inhibition of cyclooxygenase

Answer

Inhibition of thromboxane synthetase

Answer

Decreased serum lipids

Answer

Coronary steal phenomenon

Question 10

Acanthosis nigricans can be caused by which drug?

Accepted Answer

Nicotinic acid

Answer

Amphotericin-B

Answer

Ketoconazole

Answer

Nalidixic acid

Cardiovascular Drugs — MCQs

Cardiovascular Drugs — MCQs

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