Cardiovascular Drugs Practice Questions

Q: Which of the following plasminogen activators (fibrinolytics) can be administered as a bolus dose in patients with acute myocardial infarction?

Reteplase. **Explanation:** The correct answer is **Reteplase**. The primary factor determining whether a fibrinolytic can be given as a bolus dose is its **plasma half-life**. **Why Reteplase is correct:** Reteplase is a genetically engineered, non-glycosylated form of recombinant tissue plasminogen activator (rt-PA). It has a longer half-life (approximately 15–18 minutes) compared to native alteplase. This extended duration allows it to be administered as **two intravenous bolus injections** (10 units each, 30 minutes apart) rather than a continuous infusion. This simplifies administration in emergency settings like Acute Myocardial Infarction (AMI). **Why other options are incorrect:** * **Alteplase (rt-PA):** It has a very short half-life (3–5 minutes). Consequently, it requires a complex **"accelerated infusion"** regimen (a small initial bolus followed by a continuous IV infusion over 90 minutes) to maintain therapeutic levels. * **Urokinase:** It is a non-fibrin-specific activator with a short half-life (12–20 minutes) but is traditionally administered via **continuous intravenous infusion** for conditions like pulmonary embolism or peripheral arterial occlusion, rather than a rapid bolus for AMI. **High-Yield NEET-PG Pearls:** 1. **Tenecteplase (TNK-tPA):** This is the most fibrin-specific agent with the longest half-life. It is administered as a **single weight-based IV bolus**, making it the preferred agent for pre-hospital thrombolysis. 2. **Fibrin Specificity:** Alteplase, Reteplase, and Tenecteplase are fibrin-specific (clot-selective), whereas Streptokinase and Urokinase are non-specific (systemic lytic state). 3. **Antigenicity:** Streptokinase is the only highly antigenic agent; it can cause anaphylaxis and cannot be repeated within 6–12 months due to neutralizing antibodies.

Q: Which of the following is the drug of choice in treating suicidal overdose of digitoxin?

Digibind antibodies. **Explanation:** **Correct Answer: A. Digibind antibodies** Digibind (Digoxin-specific antibody fragments or Fab) is the definitive antidote and **drug of choice** for life-threatening digitalis toxicity (both Digoxin and Digitoxin). These fragments bind to free glycoside molecules in the extracellular space, creating a complex that is excreted by the kidneys. This rapidly lowers the concentration of free drug, reversing toxic effects like life-threatening arrhythmias and hyperkalemia. **Why incorrect options are wrong:** * **B. Lignocaine:** While Lignocaine is the drug of choice for treating **digitalis-induced ventricular arrhythmias**, it does not treat the underlying toxicity or neutralize the drug. * **C. Magnesium:** Magnesium is useful for managing arrhythmias, especially in patients with low magnesium levels, but it is an adjunctive therapy, not the primary antidote. * **D. Potassium:** Potassium is used to treat digitalis toxicity because it competes with digitalis for the Na+/K+ ATPase pump. However, in **acute suicidal overdose**, patients often present with **hyperkalemia** (due to total pump inhibition). Giving more potassium in this scenario is contraindicated and potentially fatal. **High-Yield Clinical Pearls for NEET-PG:** 1. **Mechanism of Action:** Digitalis inhibits the Na+/K+ ATPase pump, leading to increased intracellular Na+ and subsequently increased intracellular Ca2+ via the Na+/Ca2+ exchanger. 2. **Earliest Symptom:** Anorexia, nausea, and vomiting. 3. **Most Common Arrhythmia:** Ventricular Bigeminy. 4. **Most Characteristic Arrhythmia:** Paroxysmal Atrial Tachycardia (PAT) with AV block. 5. **Visual Disturbance:** Xanthopsia (yellowish-green vision). 6. **Digitoxin vs. Digoxin:** Digitoxin has a longer half-life (~7 days) and is primarily metabolized by the liver, making it "safer" in renal failure compared to Digoxin.

Q: Which calcium channel blocker is used in the treatment of hypertension?

Nifedipine. ### Explanation **Correct Answer: D. Nifedipine** **Mechanism and Rationale:** Calcium Channel Blockers (CCBs) inhibit the entry of calcium ions through **L-type voltage-gated calcium channels** in vascular smooth muscle and myocardium. **Nifedipine** belongs to the **Dihydropyridine (DHP)** class of CCBs. Its primary action is potent peripheral vasodilation, which reduces total peripheral resistance (TPR), thereby lowering blood pressure. It is a first-line agent for managing chronic hypertension and is also used in Raynaud’s phenomenon. **Analysis of Incorrect Options:** * **A. Prazosin:** This is a selective **alpha-1 ($\alpha_1$) adrenergic blocker**. While it is used for hypertension and Benign Prostatic Hyperplasia (BPH), it is not a calcium channel blocker. * **B. Lidoflazine:** This is a piperazine derivative classified as a calcium channel blocker, but it was historically used as a **coronary vasodilator** for angina, not for the routine treatment of hypertension. It is largely obsolete due to its potential for QT prolongation. * **C. Captopril:** This is an **ACE (Angiotensin-Converting Enzyme) Inhibitor**. It lowers blood pressure by preventing the conversion of Angiotensin I to Angiotensin II, a potent vasoconstrictor. **High-Yield Clinical Pearls for NEET-PG:** * **DHP vs. Non-DHP:** DHPs (Nifedipine, Amlodipine) are potent vasodilators. Non-DHPs (Verapamil, Diltiazem) have significant negative inotropic and chronotropic effects (act on the heart). * **Side Effects:** A common side effect of Nifedipine/Amlodipine is **ankle edema** (due to precapillary vasodilation) and reflex tachycardia. * **Drug of Choice:** CCBs are preferred antihypertensives in elderly patients and those of African descent. * **Nimodipine:** A DHP CCB specifically used to prevent cerebral vasospasm in **Subarachnoid Hemorrhage (SAH)**.

Q: Beta-blockers are used in all of the following conditions except?

AV block. **Explanation:** The correct answer is **AV block** because beta-blockers are strictly contraindicated in this condition. **1. Why AV block is the correct answer:** Beta-blockers exert **negative dromotropic** effects, meaning they slow down conduction through the Atrioventricular (AV) node by blocking $\beta_1$ receptors. In a patient already suffering from AV block (especially 2nd or 3rd degree), beta-blockers can further depress conduction, potentially leading to complete heart block, severe bradycardia, or asystole. **2. Why other options are incorrect:** * **Essential Tremors:** Propranolol (a non-selective beta-blocker) is the drug of choice. It acts on peripheral $\beta_2$ receptors in the skeletal muscles to reduce the amplitude of tremors. * **Angina Pectoris:** Beta-blockers are first-line agents. They reduce myocardial oxygen demand by decreasing heart rate (negative chronotropy) and contractility (negative inotropy). * **Migraine Prophylaxis:** Propranolol is a first-line agent for preventing migraine attacks (though it does not treat acute attacks). Its mechanism likely involves stabilizing vascular tone and reducing cortical excitability. **Clinical Pearls for NEET-PG:** * **Contraindications (ABCDE):** **A**sthma/COPD, **B**lock (Heart block), **C**onfused states (Depression), **D**iabetes mellitus (masks hypoglycemia), **E**lectrolyte imbalance (Hyperkalemia). * **Drug of Choice:** Propranolol is the DOC for **Performance Anxiety** and **Thyroid Storm** (it inhibits peripheral conversion of T4 to T3). * **Cardioselective Beta-blockers (A to M):** **A**tenolol, **B**isoprolol, **E**smolol (shortest acting), **M**etoprolol. These are preferred in patients with mild COPD or Diabetes.

Q: Captopril can cause all of the following except:

Decrease in K+ concentration. **Explanation:** **Captopril** is an ACE (Angiotensin-Converting Enzyme) inhibitor. To understand its side effects, one must look at the Renin-Angiotensin-Aldosterone System (RAAS) blockade. **1. Why "Decrease in K+ concentration" is the correct answer:** ACE inhibitors block the conversion of Angiotensin I to Angiotensin II. Since Angiotensin II normally stimulates the adrenal cortex to release **aldosterone**, its inhibition leads to a decrease in aldosterone levels. Aldosterone is responsible for sodium reabsorption and potassium excretion in the distal tubule. Therefore, a decrease in aldosterone results in **potassium retention (Hyperkalemia)**, not a decrease in K+ concentration. **2. Analysis of incorrect options:** * **Decrease in afterload:** Angiotensin II is a potent vasoconstrictor. By blocking its production, ACE inhibitors cause systemic vasodilation, which directly reduces Total Peripheral Resistance (TPR) and afterload. * **Proteinuria:** While ACE inhibitors are generally nephroprotective in diabetics, Captopril (specifically due to its sulfhydryl group) has been associated with membranous glomerulopathy and proteinuria, especially at high doses. * **Blood dyscrasia:** Captopril can rarely cause neutropenia or agranulocytosis, particularly in patients with renal impairment or collagen vascular diseases. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for ACEI side effects (CAPTOPRIL):** **C**ough (due to Bradykinin), **A**ngioedema, **P**roteinuria/ **P**otassium excess, **T**aste changes (dysgeusia), **O**rthostatic hypotension, **P**regnancy contraindicated (Teratogenic), **R**enal artery stenosis (contraindicated), **I**ncreased renin, **L**eukopenia. * **First-dose hypotension** is a common phenomenon with ACE inhibitors. * Captopril is unique among ACE inhibitors because it contains a **sulfhydryl group**, which is linked to the higher incidence of skin rashes and taste disturbances.

Q: Which of the following statements is NOT true about nesiritide?

It has significant oral absorption.. ### Explanation **Nesiritide** is a recombinant form of human **B-type Natriuretic Peptide (BNP)**. Understanding its pharmacokinetic profile is crucial for NEET-PG. **Why Option C is the correct answer (The False Statement):** Nesiritide is a **polypeptide**. Like insulin or other protein-based drugs, it would be rapidly degraded by proteolytic enzymes in the gastrointestinal tract if taken orally. Therefore, it has **zero oral bioavailability** and must be administered exclusively via the **intravenous (IV)** route. **Analysis of Other Options:** * **Option A:** Nesiritide is indeed a recombinant B-type (Brain) Natriuretic Peptide analogue. It works by increasing intracellular cGMP, leading to smooth muscle relaxation. * **Option B:** Its primary clinical indication is **acutely decompensated heart failure (ADHF)** with dyspnea at rest. It provides "balanced" vasodilation (reducing both preload via venodilation and afterload via arteriodilation) and promotes natriuresis. * **Option D:** It has a very **short half-life** (approximately 18–20 minutes), necessitating administration as an IV bolus followed by a continuous infusion. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Binds to particulate guanylate cyclase receptor (NPR-A), increasing **cGMP**. * **Effects:** Vasodilation, natriuresis (sodium excretion), and diuresis; it lacks direct inotropic effects. * **Major Side Effect:** **Hypotension** is the most common dose-limiting adverse effect. Some studies also suggest a risk of worsening renal function. * **Mnemonic:** **N**esiritide = **N**atriuretic peptide for **N**ew (Acute) heart failure.

Q: Bosentan is:

An endothelin receptor blocker. **Explanation:** **Bosentan** is a non-selective, competitive antagonist of **Endothelin-1 (ET-1)** receptors. It blocks both **$ET_A$** and **$ET_B$** receptors. Endothelin-1 is one of the most potent endogenous vasoconstrictors; by blocking its action, Bosentan decreases pulmonary vascular resistance. It is primarily used in the management of **Pulmonary Arterial Hypertension (PAH)** (WHO Group 1) to improve exercise capacity and decrease clinical worsening. **Analysis of Incorrect Options:** * **Option B (ACE Inhibitor):** Drugs in this class (e.g., Enalapril, Lisinopril) inhibit the Angiotensin-Converting Enzyme, preventing the conversion of Angiotensin I to Angiotensin II. They are used for systemic hypertension and heart failure, not pulmonary-specific vasoconstriction pathways. * **Option C (IIb/IIIa receptor blocker):** These are antiplatelet agents (e.g., Abciximab, Eptifibatide, Tirofiban) that block the Glycoprotein IIb/IIIa receptor on platelets, preventing fibrinogen binding and platelet aggregation. **High-Yield Clinical Pearls for NEET-PG:** * **Route:** It is administered orally. * **Adverse Effects:** The most significant side effect is **Hepatotoxicity** (elevation of serum transaminases); therefore, monthly Liver Function Tests (LFTs) are mandatory. * **Teratogenicity:** It is highly teratogenic (Category X) and contraindicated in pregnancy. * **Other Endothelin Antagonists:** * **Ambrisentan:** Selective $ET_A$ receptor antagonist (less hepatotoxic). * **Macitentan:** Tissue-targeting non-selective antagonist with a longer half-life.

Question 1

Which of the following plasminogen activators (fibrinolytics) can be administered as a bolus dose in patients with acute myocardial infarction?

Accepted Answer

Reteplase

Answer

Urokinase

Answer

Alteplase

Answer

None of the above

Question 2

Which of the following is the drug of choice in treating suicidal overdose of digitoxin?

Accepted Answer

Digibind antibodies

Answer

Lignocaine

Answer

Magnesium

Answer

Potassium

Question 3

Which antihypertensive agent is most commonly associated with causing impotence?

Accepted Answer

Beta-blockers

Answer

Calcium channel blocker

Answer

ACE inhibitors

Answer

Angiotensin II receptor antagonists

Question 4

Which calcium channel blocker is used in the treatment of hypertension?

Accepted Answer

Nifedipine

Answer

Prazosin

Answer

Lidoflazine

Answer

Captopril

Question 5

Beta-blockers are used in all of the following conditions except?

Accepted Answer

AV block

Answer

Essential tremors

Answer

Angina pectoris

Answer

Migraine prophylaxis

Question 6

Captopril can cause all of the following except:

Accepted Answer

Decrease in K+ concentration

Answer

Decrease in afterload

Answer

Proteinuria

Answer

Blood dyscrasia

Question 7

Which of the following statements is NOT true about nesiritide?

Accepted Answer

It has significant oral absorption.

Answer

It is a brain natriuretic peptide analogue.

Answer

It is used in acutely decompensated heart failure.

Answer

It has a short half-life.

Question 8

Metoprolol is preferred over propranolol in some patients because it:

Accepted Answer

is less likely to cause bronchoconstriction

Answer

causes less cardiac depression

Answer

has both alpha- and beta-adrenoceptor blocking effects

Answer

is more effective as an antiarrhythmic

Question 9

Bosentan is:

Accepted Answer

An endothelin receptor blocker

Answer

An ACE inhibitor

Answer

A IIb/IIIa receptor blocker

Answer

None of the above

Question 10

Propranolol is useful in the treatment of all of the following EXCEPT:

Accepted Answer

Partial atrioventricular block

Answer

Angina

Answer

Idiopathic hypertrophic subaortic stenosis

Answer

Familial tremor

Cardiovascular Drugs — MCQs

Cardiovascular Drugs — MCQs

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