Cardiovascular Drugs Practice Questions

Q: Which of the following agents is a Neprilysin inhibitor?

Sacubitril. **Explanation:** **Sacubitril** is a prodrug that, upon activation to sacubitrilat, inhibits the enzyme **Neprilysin** (neutral endopeptidase). Neprilysin is responsible for the degradation of endogenous vasoactive peptides, including Atrial Natriuretic Peptide (ANP), B-type Natriuretic Peptide (BNP), and bradykinin. By inhibiting this enzyme, Sacubitril increases the levels of these peptides, leading to vasodilation, natriuresis, and diuresis, which counteracts the maladaptive vasoconstriction and fluid retention seen in heart failure. **Analysis of Incorrect Options:** * **Carperitide:** This is a recombinant form of human **Atrial Natriuretic Peptide (ANP)**. It acts as an agonist at natriuretic peptide receptors, not as an enzyme inhibitor. * **Neseritide:** This is a recombinant form of human **B-type Natriuretic Peptide (BNP)** used in acute decompensated heart failure. Like Carperitide, it is a peptide analog, not a neprilysin inhibitor. * **Ularitide:** This is a synthetic form of **Urodilatin** (a natriuretic peptide produced in the kidneys). It also functions as a receptor agonist. **High-Yield Clinical Pearls for NEET-PG:** * **ARNI:** Sacubitril is clinically used in a fixed-dose combination with Valsartan (an ARB), known as an **Angiotensin Receptor-Neprilysin Inhibitor (ARNI)**. * **Indication:** It is a first-line therapy for Heart Failure with Reduced Ejection Fraction (HFrEF) to reduce mortality and hospitalizations. * **Contraindication:** It must **not** be administered with an ACE inhibitor due to a significantly increased risk of **angioedema** (both drugs prevent the breakdown of bradykinin). A washout period of **36 hours** is required when switching from an ACE inhibitor to an ARNI.

Q: Combination use of beta blockers and calcium channel blockers can cause which of the following?

All of these. ### Explanation The combination of **Beta-blockers (BBs)** and **Calcium Channel Blockers (CCBs)**, particularly the non-dihydropyridines like **Verapamil** and **Diltiazem**, is generally avoided or used with extreme caution due to their synergistic inhibitory effects on the heart. **Why "All of these" is correct:** Both BBs and non-dihydropyridine CCBs exert negative inotropic (force), negative chronotropic (rate), and negative dromotropic (conduction) effects. 1. **Heart Block:** Both drug classes depress the **Atrioventricular (AV) node**. When combined, they significantly prolong the PR interval, which can progress to complete heart block. 2. **Bradycardia:** Both classes suppress the **Sinoatrial (SA) node** firing rate. Their additive effect can lead to severe sinus bradycardia. 3. **Hypotension:** BBs reduce cardiac output, while CCBs cause peripheral vasodilation and further reduce myocardial contractility. Together, they can lead to a profound drop in blood pressure. **Evaluation of Options:** * **A, B, and C** are all individual physiological consequences of the combined pharmacodynamic profile of these drugs. Since all three occur simultaneously or as part of the same clinical picture, "All of these" is the most comprehensive answer. **High-Yield Clinical Pearls for NEET-PG:** * **The "Verapamil Rule":** Intravenous Verapamil is strictly contraindicated in patients already taking Beta-blockers due to the high risk of asystole. * **Dihydropyridines (e.g., Amlodipine):** These are safer to combine with BBs because they primarily cause vasodilation and may even trigger reflex tachycardia, which BBs help counteract. * **Antidote:** In cases of toxicity from this combination, **Glucagon** is the drug of choice as it increases cAMP levels in the heart via non-adrenergic pathways, bypassing the blocked receptors.

Q: Which of the following is not a centrally acting hypertensive agent?

Minoxidil. **Explanation:** The question asks to identify the drug that does **not** act via the central nervous system to lower blood pressure. **1. Why Minoxidil is the Correct Answer:** Minoxidil is a **direct-acting peripheral vasodilator**. Its mechanism of action involves opening **ATP-sensitive potassium channels ($K_{ATP}$)** in vascular smooth muscle. This leads to potassium efflux, hyperpolarization, and subsequent relaxation of arterioles (not veins). Because it acts directly on the blood vessels and not the brain, it is not a centrally acting agent. **2. Analysis of Incorrect Options (Centrally Acting Agents):** * **Clonidine:** A prototypical central **$\alpha_2$-adrenergic agonist**. It stimulates $\alpha_2$ receptors in the nucleus tractus solitarius (NTS), decreasing sympathetic outflow from the vasomotor center. * **Methyldopa:** A prodrug converted to $\alpha$-methylnorepinephrine in the brain. It acts as a central **$\alpha_2$ agonist**, making it the drug of choice for hypertension in pregnancy. * **Moxonidine:** A selective **imidazoline $I_1$ receptor agonist** in the rostral ventrolateral medulla. It reduces sympathetic activity with fewer sedative side effects than clonidine. **3. NEET-PG High-Yield Pearls:** * **Minoxidil Side Effects:** Significant reflex tachycardia and salt/water retention (usually co-prescribed with a beta-blocker and diuretic). It also causes **hypertrichosis** (used topically for alopecia). * **Clonidine Withdrawal:** Abrupt cessation leads to a **rebound hypertensive crisis** due to a sudden surge in catecholamines. * **Methyldopa Side Effect:** Can cause a **positive Coombs test** and rare hemolytic anemia.

Q: Which of the following conditions precipitates Digoxin toxicity?

Hypokalemia. **Explanation:**Digoxin works by inhibiting the **Na⁺/K⁺-ATPase pump** on the myocardial cell membrane. Under normal physiological conditions, potassium (K⁺) ions compete with Digoxin for the same binding site on this ATPase pump. In **Hypokalemia (Option A)**, there is less extracellular potassium available to compete for these binding sites. This allows more Digoxin to bind to the pump, leading to excessive inhibition and an exaggerated pharmacological effect, which precipitates **Digoxin toxicity** [2]. Even "normal" therapeutic levels of Digoxin can become toxic in the presence of low potassium. **Analysis of Incorrect Options:** * **Hyperkalemia (Option B):** High potassium levels increase competition for the binding site, effectively reducing Digoxin’s binding and action. While hyperkalemia can *antagonize* Digoxin, it does not precipitate toxicity [1] (though severe toxicity itself can cause hyperkalemia due to pump paralysis). * **Hypernatremia (Option C) & Hyperphosphatemia (Option D):** Sodium and phosphate levels do not directly compete with Digoxin at its binding site on the Na⁺/K⁺-ATPase pump and are not primary triggers for toxicity. **High-Yield Clinical Pearls for NEET-PG:** * **Electrolyte Triad of Toxicity:** Digoxin toxicity is precipitated by **Hypokalemia, Hypomagnesemia, and Hypercalcemia** ("Hi-Cal, Low-Mag, Low-K") [2]. * **ECG Changes:** The most common initial sign of toxicity is **PVCs** (Premature Ventricular Contractions). The most characteristic arrhythmia is **Atrial Tachycardia with AV block**. * **Visual Disturbance:** Patients may report **Xanthopsia** (yellow-green halos around lights). * **Antidote:** Digoxin-specific antibody fragments (**DigiFab**).

Q: All of the following statements are true about quinidine except?

It has no effect on myocardial K+ channels.. Explanation: Quinidine is a prototype Class IA antiarrhythmic drug. To answer this question, one must understand the "Vaughan-Williams classification" and the specific electrophysiological properties of Class IA agents [2]. 1. Why Option B is the correct answer (The False Statement): Contrary to the statement, Quinidine does block myocardial K+ channels (specifically the delayed rectifier current, $I_{Kr}$) [1]. By blocking potassium channels, it prolongs the action potential duration (APD) and the effective refractory period (ERP). This K+ channel blockade is also responsible for the side effect of QT interval prolongation, which can predispose patients to Torsades de Pointes [3]. 2. Analysis of Incorrect Options (True Statements): * Option A & C: Quinidine is a sodium (Na+) channel blocker [1]. It shows "state-dependency," meaning it binds preferentially to channels in the open or activated state. Because it binds more effectively when channels are firing frequently, it exhibits "frequency-dependent" (or use-dependent) blockade, making it more effective in tachyarrhythmias [2]. * Option D: Class IA drugs are characterized by intermediate dissociation kinetics. They delay the recovery of Na+ channels from the inactivated state, thereby increasing the threshold for excitability. High-Yield Clinical Pearls for NEET-PG: * Cinchonism: A classic side effect triad of tinnitus, headache, and dizziness [1]. * Vagolytic Effect: Quinidine has atropine-like (antimuscarinic) properties, which can paradoxically increase AV conduction. * Drug Interaction: Quinidine reduces the renal clearance of Digoxin, leading to digoxin toxicity. * ECG Changes: Widened QRS (Na+ block) and prolonged QT (K+ block).

Q: Postural hypotension and failure of ejaculation is most commonly seen in treatment with?

Guanethedine. **Explanation:** **Guanethidine** is the correct answer because it is an **adrenergic neuron blocker**. It works by inhibiting the release of norepinephrine from postganglionic sympathetic nerve endings and displacing stored norepinephrine, leading to a gradual depletion of catecholamines [1]. 1. **Postural Hypotension:** By blocking the sympathetic outflow, Guanethidine prevents the compensatory vasoconstriction required when a person stands up, leading to a significant drop in blood pressure [1], [2]. 2. **Failure of Ejaculation:** Ejaculation is a sympathetic-mediated process ("S" for Sympathetic = Shoot). Guanethidine’s blockade of peripheral sympathetic nerves prevents the contraction of the vas deferens and seminal vesicles, leading to ejaculatory failure. **Analysis of Incorrect Options:** * **Minoxidil:** A potent direct-acting vasodilator (K+ channel opener). It typically causes reflex tachycardia and fluid retention, not postural hypotension or ejaculatory issues. * **Propranolol:** A non-selective beta-blocker. While it can cause erectile dysfunction (impotence), it does not typically cause failure of ejaculation or significant postural hypotension (as alpha-receptors remain intact for vasoconstriction). * **Sodium Nitroprusside:** A balanced vasodilator (arteriolar and venous) used in hypertensive emergencies. While it can cause a rapid drop in BP, it is administered IV in a controlled setting and is not associated with chronic ejaculatory failure. **High-Yield Clinical Pearls for NEET-PG:** * **"Triple Action" of Guanethidine:** It inhibits release, inhibits reuptake (Uptake-1), and depletes stores of NE [1]. * **Drug Interaction:** Tricyclic Antidepressants (TCAs) and Cocaine block the uptake of Guanethidine into the neuron, reversing its antihypertensive effect [1]. * **Mnemonic:** Sympathetic = **S**hoot (Ejaculation); Parasympathetic = **P**oint (Erection). Guanethidine affects the "Shoot."

Q: Which of the following is the best inotropic drug for use in right heart failure?

Milrinone. **Explanation:** The management of right heart failure (RHF) requires a drug that simultaneously increases myocardial contractility (inotropy) and reduces the afterload on the right ventricle by decreasing pulmonary vascular resistance (PVR). **Why Milrinone is the Correct Answer:** Milrinone is a **Phosphodiesterase-3 (PDE3) inhibitor**. It works by increasing intracellular cAMP in cardiac and smooth muscle cells. This leads to two synergistic effects: 1. **Inotropy:** Increases cardiac contractility. 2. **Inodilatation:** Causes potent systemic and, more importantly, **pulmonary vasodilation**. By reducing pulmonary artery pressure, Milrinone decreases the workload of the thin-walled right ventricle, making it the "gold standard" inotropic agent for RHF and pulmonary hypertension. **Analysis of Incorrect Options:** * **Dobutamine (Option A):** While an excellent inotrope ($\beta_1$ agonist), it has less predictable effects on pulmonary vascular resistance compared to Milrinone and can increase myocardial oxygen demand significantly. * **Dopamine (Option B):** At higher doses, it causes $\alpha_1$-mediated vasoconstriction, which can increase pulmonary artery pressures and worsen the strain on the right ventricle. * **Digoxin (Option C):** It has a slow onset of action and weak inotropic effects; it is not used for the acute management of right heart failure. **High-Yield Clinical Pearls for NEET-PG:** * **Milrinone Side Effect:** The most common side effect is **hypotension** due to systemic vasodilation; it may require a concurrent vasopressor (like Noradrenaline). * **Renal Clearance:** Milrinone is renally excreted; doses must be adjusted in patients with renal impairment. * **Inodilator Concept:** Remember that Milrinone and Levosimendan are classified as "inodilators." * **Right Ventricle (RV):** Unlike the left ventricle, the RV is highly sensitive to afterload; therefore, reducing PVR is the cornerstone of RHF therapy.

Q: Which one of the following antihypertensive drugs is contraindicated in pregnancy?

Furosemide. ### Explanation **Correct Option: D. Furosemide** **Why Furosemide is Contraindicated:** Furosemide is a potent loop diuretic. In pregnancy, it is generally avoided because it can cause **placental hypoperfusion**. Diuretics reduce maternal plasma volume, which may interfere with the physiological volume expansion necessary for a healthy pregnancy. This can lead to decreased uterine blood flow, potentially causing fetal growth restriction or neonatal complications. Additionally, it crosses the placental barrier and can cause electrolyte imbalances in the fetus. **Analysis of Incorrect Options:** * **A. Alpha-methyldopa:** This is a centrally acting alpha-2 agonist and has traditionally been the **drug of choice (DOC)** for chronic hypertension in pregnancy due to its long-term safety profile for both mother and fetus. * **B. Hydralazine:** A direct vasodilator used primarily in the management of **acute hypertensive emergencies** in pregnancy (e.g., severe pre-eclampsia). It is considered safe for rapid blood pressure reduction. * **C. Nifedipine:** A calcium channel blocker (dihydropyridine) that is frequently used as a first-line oral agent for maintenance therapy and as a tocolytic to delay preterm labor. **High-Yield NEET-PG Pearls:** 1. **Absolute Contraindications:** ACE inhibitors (e.g., Enalapril) and ARBs (e.g., Losartan) are strictly contraindicated due to **teratogenicity** (renal dysgenesis, skull hypoplasia, and oligohydramnios). Direct Renin Inhibitors (Aliskiren) and Statins are also contraindicated. 2. **Safe Antihypertensives (Mnemonic: Better Mother Love Next-generation):** **B**eta-blockers (Labetalol), **M**ethyldopa, **L**abetalol (often DOC now), **N**ifedipine. 3. **Labetalol** is currently preferred over Methyldopa in many guidelines due to a faster onset and fewer side effects (like sedation).

Q: Which of the following is an active metabolite of another drug and is available as a separate drug for the treatment of angina?

Isosorbide mononitrate. **Explanation:** The correct answer is **Isosorbide mononitrate (ISMN)**. **1. Why Isosorbide mononitrate is correct:** Isosorbide dinitrate (ISDN) undergoes extensive first-pass metabolism in the liver, where it is converted into two active metabolites: **Isosorbide-2-mononitrate** and **Isosorbide-5-mononitrate**. Among these, Isosorbide-5-mononitrate is the major metabolite. It has been developed as a separate drug because it possesses **100% oral bioavailability** (unlike the parent drug ISDN) and a longer half-life, making it highly effective for the chronic prophylaxis of angina pectoris. **2. Why other options are incorrect:** * **Isosorbide dinitrate (ISDN):** This is the parent prodrug. While effective, it has low oral bioavailability (~20-25%) due to significant hepatic metabolism. * **Nitroglycerine (Glyceryl Trinitrate):** This is a parent drug, not a metabolite of another anti-anginal. It undergoes near-total first-pass metabolism, which is why it is typically administered sublingually for acute attacks. * **Propranolol:** This is a non-selective beta-blocker. While used in chronic angina to reduce myocardial oxygen demand, it is a parent drug and its active metabolite (4-hydroxypropranolol) is not marketed as a separate anti-anginal agent. **High-Yield Clinical Pearls for NEET-PG:** * **Bioavailability:** ISMN is the only organic nitrate that does not undergo significant first-pass metabolism (Bioavailability ≈ 100%). * **Nitrate Tolerance:** To prevent tolerance, a "nitrate-free interval" of 8–12 hours (usually at night) is mandatory. * **Drug Interaction:** Nitrates are strictly contraindicated with **Sildenafil** (PDE-5 inhibitors) due to the risk of severe, fatal hypotension. * **Monday Disease:** Chronic exposure to nitrates in ammunition factories leads to tolerance; loss of this tolerance over the weekend results in "Monday morning headaches" due to sudden vasodilation.

Question 1

Which of the following agents is a Neprilysin inhibitor?

Accepted Answer

Sacubitril

Answer

Carperitide

Answer

Neseritide

Answer

Ularitide

Question 2

Combination use of beta blockers and calcium channel blockers can cause which of the following?

Accepted Answer

All of these

Answer

Heart block

Answer

Hypotension

Answer

Bradycardia

Question 3

Which of the following is not a centrally acting hypertensive agent?

Accepted Answer

Minoxidil

Answer

Methyldopa

Answer

Moxonidine

Answer

Clonidine

Question 4

All of the following electrocardiographic findings may represent manifestations of digitalis intoxication, EXCEPT?

Accepted Answer

Atrial flutter

Answer

Bigeminy

Answer

Junctional tachycardia

Answer

Atrial tachycardia with variable block

Question 5

Which of the following conditions precipitates Digoxin toxicity?

Accepted Answer

Hypokalemia

Answer

Hyperkalemia

Answer

Hypernatremia

Answer

Hyperphosphatemia

Question 6

All of the following statements are true about quinidine except?

Accepted Answer

It has no effect on myocardial K+ channels.

Answer

It blocks myocardial Na+ channels primarily in the open state.

Answer

It produces frequency dependent blockade of myocardial Na+ channels.

Answer

It delays recovery of myocardial Na+ channels.

Question 7

Postural hypotension and failure of ejaculation is most commonly seen in treatment with?

Accepted Answer

Guanethedine

Answer

Minoxidil

Answer

Propranolol

Answer

Sodium nitroprusside

Question 8

Which of the following is the best inotropic drug for use in right heart failure?

Accepted Answer

Milrinone

Answer

Dobutamine

Answer

Dopamine

Answer

Digoxin

Question 9

Which one of the following antihypertensive drugs is contraindicated in pregnancy?

Accepted Answer

Furosemide

Answer

Alpha methyldopa

Answer

Hydralazine

Answer

Nifedipine

Question 10

Which of the following is an active metabolite of another drug and is available as a separate drug for the treatment of angina?

Accepted Answer

Isosorbide mononitrate

Answer

Isosorbide dinitrate

Answer

Nitroglycerine

Answer

Propranolol

Cardiovascular Drugs — MCQs

Cardiovascular Drugs — MCQs

On this page

Practice by Chapter

Want unlimited practice?