Cardiovascular Drugs Practice Questions

Q: The dose of digoxin is NOT altered in which of the following conditions?

Hepatic disease. **Explanation:** The correct answer is **Hepatic disease** because of the pharmacokinetic profile of Digoxin. **1. Why Hepatic Disease is the correct answer:** Digoxin is a polar glycoside that is primarily excreted **unchanged by the kidneys** (approx. 60-80%) via glomerular filtration and tubular secretion (P-glycoprotein mediated) [2], [3]. It undergoes minimal hepatic metabolism [2]. Therefore, its clearance is not significantly affected by liver dysfunction, and dose adjustment is generally not required in patients with hepatic disease [1]. **2. Why the other options are incorrect:** * **Old Age:** Renal function naturally declines with age (reduced GFR). Additionally, elderly patients have lower skeletal muscle mass (the primary tissue reservoir for digoxin), leading to higher serum levels. Dose reduction is mandatory to avoid toxicity. * **Renal Disease:** Since the kidneys are the primary route of elimination, any degree of renal impairment increases the half-life of digoxin significantly (from 36 hours up to 5 days), necessitating strict dose reduction based on creatinine clearance [2], [3]. * **Hypercalcemia:** Digoxin works by inhibiting the Na+/K+ ATPase pump, which indirectly increases intracellular calcium. Hypercalcemia synergizes with digoxin, increasing the risk of cardiac arrhythmias. In this state, the heart is "sensitized" to digoxin, requiring a lower dose or cautious monitoring [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Digitoxin vs. Digoxin:** Unlike Digoxin, **Digitoxin** is primarily metabolized by the liver and is the drug of choice in patients with renal failure (though rarely used now) [2]. * **Electrolyte Triad:** Digoxin toxicity is precipitated by **Hypokalemia, Hypomagnesemia, and Hypercalcemia.** * **Monitoring:** The therapeutic range for digoxin is narrow (**0.5–2 ng/mL**) [2]. * **Antidote:** Digibind (Digoxin-specific Fab fragments) is used for life-threatening toxicity.

Q: Antihypertensives may act by blocking all of the following except?

ATP dependent potassium channels. To understand this question, one must distinguish between **blocking** a channel/receptor and **activating** it to achieve a therapeutic effect. ### 1. Why Option B is Correct (The Concept) Antihypertensives do not work by *blocking* ATP-dependent potassium ($K_{ATP}$) channels; instead, they act as **Potassium Channel Openers** [2]. * **Mechanism:** Drugs like **Minoxidil, Diazoxide, and Nicorandil** open these channels, leading to an efflux of $K^+$ ions [2]. * **Result:** This causes membrane hyperpolarization, which prevents the opening of voltage-gated calcium channels, leading to smooth muscle relaxation and potent vasodilation. * **Note:** Blocking these channels (e.g., by Sulfonylureas) actually leads to depolarization and is used in treating Diabetes Mellitus, not hypertension. ### 2. Why Other Options are Incorrect * **Alpha adrenoceptors (A):** Drugs like **Prazosin and Phenoxybenzamine** block $\alpha_1$ receptors, preventing vasoconstriction and lowering peripheral resistance [1], [5]. * **Noradrenaline release (C):** Adrenergic neuron blockers like **Guanethidine and Reserpine** act by inhibiting the release or storage of noradrenaline, thereby reducing sympathetic tone [3]. * **Beta adrenoceptors (D):** Drugs like **Propranolol and Atenolol** block $\beta_1$ receptors in the heart (reducing cardiac output) and the kidney (reducing renin release) [1], [5]. ### 3. High-Yield Clinical Pearls for NEET-PG * **Minoxidil Side Effect:** Can cause **hypertrichosis** (excessive hair growth), hence its use in topical formulations for alopecia. * **Diazoxide Side Effect:** Can cause **hyperglycemia** because opening $K_{ATP}$ channels in pancreatic beta cells inhibits insulin release. * **Drug of Choice:** For hypertensive emergencies in pregnancy, **Labetalol** (alpha + beta blocker) is preferred; for aortic dissection, **Esmolol** is often used [4].

Q: What is the preferred drug for the treatment of a 48-year-old man with uncomplicated grade 2 hypertension without any associated comorbidity?

Chlorthalidone. **Explanation:** The management of uncomplicated Grade 2 hypertension (BP ≥160/100 mmHg) in a patient without comorbidities follows the JNC-8 and AHA/ACC guidelines. The first-line pharmacological agents include **Thiazide-type diuretics**, ACE inhibitors, ARBs, or Calcium Channel Blockers (CCBs). **Why Chlorthalidone is correct:** Among diuretics, **Chlorthalidone** is the preferred agent over Hydrochlorothiazide (HCTZ). It is a "thiazide-like" diuretic with a significantly longer half-life (40–60 hours) and higher potency. Clinical trials (like ALLHAT) have demonstrated its superior efficacy in providing 24-hour blood pressure control and reducing cardiovascular morbidity and mortality. **Analysis of Incorrect Options:** * **B. Triamterene:** This is a potassium-sparing diuretic. It has weak antihypertensive efficacy when used alone and is typically used in combination with thiazides to prevent hypokalemia. * **C. Spironolactone:** An aldosterone antagonist used primarily in resistant hypertension, heart failure, or primary aldosteronism. It is not a first-line agent for uncomplicated hypertension due to side effects like gynecomastia. * **D. Furosemide:** A loop diuretic. While potent for fluid overload (edema, heart failure), it has a short duration of action and is less effective than thiazides for sustained blood pressure control in patients with normal renal function. **High-Yield Clinical Pearls for NEET-PG:** * **Thiazide Side Effects:** Remember the "Hyper" mnemonic: **Hyper**glycemia, **Hyper**lipidemia, **Hyper**uricemia, and **Hyper**calcemia. Conversely, they cause **Hypo**kalemia and **Hypo**natremia. * **Renal Function:** Thiazides lose efficacy when GFR is <30 mL/min (except Metolazone and Indapamide); in such cases, Loop diuretics are preferred. * **Drug of Choice:** For hypertension with **Osteoporosis**, thiazides are ideal because they decrease urinary calcium excretion.

Q: Dysgeusia is a side effect of which of the following medications?

Captopril. **Explanation:** **Captopril** is the correct answer because it is the only ACE inhibitor in the options that contains a **sulfhydryl (-SH) group**. This chemical structure is directly responsible for specific side effects not commonly seen with other ACE inhibitors, most notably **dysgeusia** (distortion of taste) and skin rashes. The sulfhydryl group can interfere with taste bud function or lead to a metallic taste. **Analysis of Options:** * **A. Captopril (Correct):** As the prototype ACE inhibitor, its sulfhydryl group is the culprit for dysgeusia and occasionally neutropenia. * **B, C, and D (Enalapril, Ramipril, Lisinopril):** These are non-sulfhydryl-containing ACE inhibitors. While they share the class side effects (like dry cough and angioedema), they are significantly less likely to cause taste disturbances. Enalapril and Ramipril are prodrugs, whereas Captopril and Lisinopril are active drugs. **High-Yield Clinical Pearls for NEET-PG:** 1. **Captopril Unique Features:** It has the shortest half-life among ACE inhibitors (requires frequent dosing) and must be taken on an empty stomach as food decreases its bioavailability. 2. **Class Side Effects (Mnemonic: CAPTOPRIL):** **C**ough (due to bradykinin), **A**ngioedema, **P**roteinuria, **T**aste changes (Dysgeusia), **O**rthostatic hypotension, **P**regnancy contraindication (Teratogenic), **R**enal artery stenosis (contraindicated in bilateral), **I**ncreased Potassium (Hyperkalemia), **L**eukopenia. 3. **Drug of Choice:** ACE inhibitors are the first-line treatment for hypertension in patients with **Diabetes Mellitus** because they provide renoprotection by dilating the efferent arteriole.

Q: Nitrates cannot be used in which of the following conditions?

Renal colic. **Explanation:** Nitrates are potent smooth muscle relaxants that act by releasing Nitric Oxide (NO), which increases cGMP levels. However, their efficacy varies across different organ systems. **Why Renal Colic is the Correct Answer:** Nitrates are **ineffective in renal colic** because the ureteric smooth muscle lacks the specific metabolic machinery or sufficient sensitivity to respond to nitrate-induced relaxation. In clinical practice, renal colic is managed with NSAIDs (to decrease prostaglandin-mediated pressure) and antispasmodics like hyoscine or tamsulosin. **Analysis of Incorrect Options:** * **Angina Pectoris:** This is the primary indication for nitrates. They cause peripheral vasodilation (venodilation > arteriodilation), which decreases preload and myocardial oxygen demand. * **Biliary Colic:** Nitrates effectively relax the **Sphincter of Oddi** and the smooth muscles of the biliary tract, providing symptomatic relief in biliary spasms. * **Cyanide Poisoning:** Amyl nitrite and sodium nitrite are used as antidotes. They induce **methemoglobinemia**; methemoglobin has a high affinity for cyanide, forming cyanmethemoglobin and preventing cyanide from binding to cytochrome oxidase. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** For acute angina, sublingual Nitroglycerin (GTN) is the DOC. * **Nitrate Tolerance:** Continuous use leads to "tachyphylaxis" due to the depletion of free sulfhydryl (-SH) groups. A "nitrate-free interval" of 8–12 hours (usually at night) is required to prevent this. * **Monday Disease:** Workers in dynamite factories experience headaches and dizziness on Mondays due to sudden re-exposure to nitrates after a weekend break. * **Contraindication:** Never co-administer nitrates with **Sildenafil** (PDE-5 inhibitors) as it can lead to life-threatening hypotension.

Q: Which of the following is associated with a prolonged QT interval?

Type Ia antiarrhythmic drugs. **Explanation:** The **QT interval** on an ECG represents the duration of ventricular depolarization and repolarization. Prolongation of this interval is primarily caused by a delay in ventricular repolarization, usually due to the inhibition of outward potassium ($K^+$) currents. **Why Option B is Correct:** **Type Ia antiarrhythmic drugs** (e.g., Quinidine, Procainamide, Disopyramide) act by blocking fast sodium ($Na^+$) channels, but they also possess significant **potassium channel blocking** properties. By inhibiting the efflux of $K^+$ during phase 3 of the cardiac action potential, they delay repolarization, thereby lengthening the action potential duration (APD) and the QT interval. **Analysis of Incorrect Options:** * **A. Hypercalcemia:** High calcium levels actually **shorten** the QT interval by accelerating the plateau phase (Phase 2) of the action potential. Conversely, *hypocalcemia* causes QT prolongation. * **C. Torsade de pointes (TdP):** This is a **consequence**, not a cause, of a prolonged QT interval. TdP is a specific type of polymorphic ventricular tachycardia that occurs when a prolonged QT interval leads to early after-depolarizations (EADs). * **D. Atrial fibrillation:** This is a supraventricular tachyarrhythmia characterized by disorganized atrial electrical activity. While it affects the rhythm and the absence of P-waves, it does not inherently prolong the QT interval. **NEET-PG High-Yield Pearls:** * **Mnemonic for QT Prolonging Drugs (ABCDE):** **A**ntiarrhythmics (Class Ia & III), **B**iotics (Macrolides, Fluoroquinolones), **C**yps (Antipsychotics/Haloperidol), **D**epressants (TCAs, SSRIs), **E**metics (Ondansetron). * **Electrolyte triggers:** Hypokalemia, hypomagnesemia, and hypocalcemia all prolong the QT interval. * **Treatment of TdP:** Intravenous **Magnesium Sulfate** is the drug of choice, even if serum magnesium levels are normal.

Q: Which of the following is true regarding enalapril treatment in patients of essential hypertension?

Decreased angiotensin II concentration in the blood. **Explanation:** Enalapril is an **ACE (Angiotensin-Converting Enzyme) Inhibitor**. To understand its effects, one must look at the Renin-Angiotensin-Aldosterone System (RAAS) pathway. **1. Why Option A is Correct:** ACE inhibitors directly block the enzyme responsible for converting Angiotensin I into **Angiotensin II**. Therefore, the primary biochemical effect of enalapril is a significant **decrease in circulating Angiotensin II levels**. This leads to vasodilation and decreased peripheral resistance. **2. Why the other options are incorrect:** * **Option B:** ACE inhibitors actually **increase plasma renin levels**. Because Angiotensin II levels fall, the negative feedback loop on the juxtaglomerular cells is lost, leading to a compensatory rise in renin secretion (pro-renin to renin). * **Option C:** By decreasing Angiotensin II, there is a subsequent decrease in **Aldosterone** secretion. Since aldosterone normally causes sodium reabsorption and potassium excretion, inhibiting it leads to **increased sodium excretion (natriuresis)** and **decreased potassium excretion** in the urine. This results in a risk of hyperkalemia, not increased potassium in the urine. **High-Yield Clinical Pearls for NEET-PG:** * **Bradykinin:** ACE inhibitors also inhibit the breakdown of bradykinin. Increased bradykinin levels are responsible for the classic side effects: **Dry cough** and **Angioedema**. * **Teratogenicity:** ACE inhibitors are strictly contraindicated in pregnancy as they cause **fetal renal anomalies** (Potter sequence). * **Drug of Choice:** They are the first-line treatment for hypertension in patients with **Diabetes Mellitus** (due to nephroprotective effects) and **Heart Failure** (reduces remodeling). * **First-dose phenomenon:** Watch out for sudden hypotension after the first dose, especially in patients on diuretics.

Question 1

The dose of digoxin is NOT altered in which of the following conditions?

Accepted Answer

Hepatic disease

Answer

Old age

Answer

Renal disease

Answer

Hypercalcemia

Question 2

Antihypertensives may act by blocking all of the following except?

Accepted Answer

ATP dependent potassium channels

Answer

Alpha adrenoceptors

Answer

Noradrenaline release

Answer

Beta adrenoceptors

Question 3

Which of the following is NOT a true statement about clonidine?

Accepted Answer

Prazosin is used to antagonize its side effects.

Answer

It increases parasympathetic outflow.

Answer

It decreases sympathetic outflow by blocking central alpha receptors.

Answer

It is used in the management of hypertension.

Question 4

What is the preferred drug for the treatment of a 48-year-old man with uncomplicated grade 2 hypertension without any associated comorbidity?

Accepted Answer

Chlorthalidone

Answer

Triamterene

Answer

Spironolactone

Answer

Furosemide

Question 5

Dysgeusia is a side effect of which of the following medications?

Accepted Answer

Captopril

Answer

Enalapril

Answer

Ramipril

Answer

Lisinopril

Question 6

All of the following statements about the antianginal action of nitrates are true EXCEPT?

Accepted Answer

Increased total coronary flow

Answer

Decreased myocardial O2 consumption

Answer

Decreased both preload and afterload

Answer

Cause favorable redistribution of coronary flow

Question 7

Nitrates cannot be used in which of the following conditions?

Accepted Answer

Renal colic

Answer

Angina pectoris

Answer

Biliary colic

Answer

Cyanide poisoning

Question 8

Which of the following is associated with a prolonged QT interval?

Accepted Answer

Type Ia antiarrhythmic drugs

Answer

Hypercalcemia

Answer

Torsade de pointes

Answer

Atrial fibrillation

Question 9

Which of the following is true regarding enalapril treatment in patients of essential hypertension?

Accepted Answer

Decreased angiotensin II concentration in the blood

Answer

Decreased concentration of renin in the blood

Answer

Decreases sodium and increases potassium in the urine

Answer

All of the above

Question 10

Which of the following statements is relevant when deciding to treat a patient with procainamide?

Accepted Answer

Procainamide prolongs the effective refractory period in atrial and ventricular cells.

Answer

Procainamide may worsen or precipitate hyperthyroidism.

Answer

Procainamide is not effective for atrial arrhythmias.

Answer

Procainamide commonly induces thrombocytopenia.

Cardiovascular Drugs — MCQs

Cardiovascular Drugs — MCQs

On this page

Practice by Chapter

Want unlimited practice?