Cardiovascular Drugs Practice Questions

Q: BETA-blockers are contraindicated in which of the following conditions?

Variant angina. ***Variant angina*** - Beta-blockers can paradoxically worsen **variant angina** by enhancing coronary vasospasm due to unopposed **alpha-receptor stimulation**, especially with non-selective agents. - This condition involves transient, focal coronary artery spasms reducing blood flow, which beta-blockers may exacerbate by inhibiting **beta-2 receptor-mediated vasodilation**. *Hypertension* - Beta-blockers are a **first-line treatment** for hypertension, particularly in patients with co-existing conditions like **angina** or **post-myocardial infarction** [2]. - They reduce blood pressure by decreasing **cardiac output** and inhibiting renin release [2]. *Thyrotoxicosis* - Beta-blockers are highly effective in managing the **symptomatic features** of thyrotoxicosis, such as **tachycardia**, palpitations, and tremor [1]. - They act by blocking the effects of **excess thyroid hormones** on beta-adrenergic receptors and can inhibit peripheral conversion of thyroxine to triiodothyronine [1]. *None of the options* - Since **variant angina** is a clear contraindication, this option is incorrect. - Beta-blockers have specific situations where their use is harmful or ineffective.

Q: All the following statements regarding adenosine are true except:

Administered by slow I.V. injection. ***Administered by slow I.V. injection*** - Adenosine has an **extremely short half-life** (less than 10 seconds), so it must be administered as a **rapid intravenous bolus** to reach the heart effectively before being metabolized. - Slow IV injection would lead to its degradation before therapeutic concentrations are achieved at its target receptors in the heart. - This statement is **FALSE** and therefore the correct answer to this EXCEPT question. *Dipyridamole potentiates its action* - **Dipyridamole** inhibits the cellular reuptake and metabolism of adenosine, increasing its extracellular concentration and thus **potentiating its effects**. - This interaction can lead to exaggerated adenosine-induced bradycardia and hypotension, so lower doses of adenosine should be used. - This statement is **TRUE**. *Used in the treatment of supraventricular tachycardia* - Adenosine is the **drug of choice** for acute termination of **paroxysmal supraventricular tachycardia (PSVT)** involving the AV node. - It works by transiently blocking AV nodal conduction, interrupting the reentrant circuit. - This statement is **TRUE**. *Administered by rapid I.V. injection* - Due to its extremely short half-life, adenosine must be given as a **rapid IV bolus** (typically over 1-2 seconds) followed immediately by a saline flush. - Rapid injection ensures sufficient drug concentration reaches the **AV node** before metabolism. - This statement is **TRUE**.

Q: Nitrates decrease myocardial oxygen consumption by all of the following mechanisms except which of the following?

By increasing the left ventricular end diastolic pressure. ***By increasing the left ventricular end diastolic pressure*** - This is the **EXCEPT** answer - nitrates do NOT work by this mechanism. - Nitrates primarily decrease **preload** by venous dilation, which leads to a **decrease** in left ventricular end-diastolic pressure (LVEDP), not an increase. - An **increased LVEDP** would raise myocardial wall tension and oxygen demand, which is **contrary** to the therapeutic effect of nitrates. - This is the only option that does NOT represent a mechanism by which nitrates reduce myocardial oxygen consumption. *By dilation of the capacitance vessels* - Nitrates cause **venodilation** (dilation of capacitance vessels), leading to venous pooling and reduced venous return. - This decreases **preload**, lowering left ventricular end-diastolic volume and pressure. - Reduced preload decreases **myocardial wall tension** and oxygen consumption (Laplace's law). *By direct reduction of oxygen consumption of the myocardial cell* - While primarily acting through hemodynamic effects, nitrates can have **some direct myocardial effects** through NO-mediated pathways. - However, this is NOT their primary mechanism - the major oxygen-sparing effects come from reducing **preload** and **afterload**. - This mechanism is less significant compared to their hemodynamic effects. *By decreasing the size of the heart* - By reducing both **preload** (venous dilation) and **afterload** (arterial dilation), nitrates decrease ventricular volume. - Smaller ventricular size reduces **myocardial wall stress** according to the **Law of Laplace** (Wall stress ∝ Pressure × Radius). - This translates to decreased myocardial oxygen consumption.

Q: Which of the following antihypertensive drugs is avoided in patients with high serum uric acid levels?

Hydrochlorothiazide. ***Hydrochlorothiazide (Correct Answer)*** - **Thiazide diuretics** like hydrochlorothiazide inhibit the sodium-chloride cotransporter in the **distal convoluted tubule**, leading to increased sodium, chloride, and water excretion - These drugs **reduce renal excretion of uric acid** by competing for secretion in the proximal tubule, leading to **hyperuricemia** - Can precipitate or exacerbate **gout attacks** in susceptible patients - Should be **avoided or used with caution** in patients with elevated serum uric acid levels *Enalapril (Incorrect)* - **ACE inhibitor** that blocks conversion of angiotensin I to angiotensin II - Causes vasodilation and reduces aldosterone secretion - Does **not significantly affect uric acid metabolism** - Safe for use in patients with hyperuricemia *Prazosin (Incorrect)* - **Alpha-1 adrenergic blocker** causing vasodilation by blocking alpha-1 receptors in vascular smooth muscle - Mechanism does **not interfere with uric acid excretion or production** - Safe option for patients with elevated serum uric acid *Atenolol (Incorrect)* - **Beta-1 selective adrenergic blocker** that reduces heart rate, cardiac output, and renin release - Does **not have clinically significant impact** on renal uric acid handling - Can be used in patients with hyperuricemia

Q: Which of the following is the best inotrope agent for use in right heart failure secondary to pulmonary hypertension?

Milrinone. ***Milrinone*** - Milrinone is a **phosphodiesterase-3 inhibitor** that increases myocardial contractility and causes **pulmonary and systemic vasodilation**. - Its vasodilatory effect is particularly beneficial in **pulmonary hypertension** as it can help reduce **pulmonary vascular resistance (PVR)**, a critical factor in right heart failure. - The combination of **positive inotropy** and **selective pulmonary vasodilation** makes it the optimal choice for right ventricular failure secondary to pulmonary hypertension. *Dobutamine* - Dobutamine is a **beta-1 agonist** that primarily increases myocardial contractility with some beta-2 mediated vasodilation. - While it improves cardiac output, its lesser effect on **pulmonary vascular resistance** compared to milrinone makes it less ideal for right heart failure specifically complicated by pulmonary hypertension. *Digoxin* - Digoxin is a **cardiac glycoside** that increases contractility but has a slow onset of action and a narrow therapeutic window, making it less suitable for acute management. - It does not significantly reduce **pulmonary vascular resistance** and is primarily used for chronic heart failure or rate control in atrial fibrillation. *Dopamine* - Dopamine is a **catecholamine** with dose-dependent effects: at moderate doses (5-10 mcg/kg/min), it acts as a **beta-1 agonist** providing inotropic support. - However, at higher doses it causes **alpha-adrenergic vasoconstriction** which can **increase pulmonary vascular resistance**, potentially worsening right heart failure in pulmonary hypertension. - Unlike milrinone, it lacks specific pulmonary vasodilatory properties beneficial for reducing RV afterload.

Q: Which of the following is a K+ channel opener?

Nicorandil. ***Nicorandil*** - **Nicorandil** opens ATP-sensitive K+ channels, causing hyperpolarization of vascular smooth muscle cells. - This K+ channel opening leads to **vasodilation** in both arteries and veins, reducing preload and afterload. *Ranolazine* - **Ranolazine** is a selective inhibitor of the late sodium current in cardiac myocytes. - Its primary action is to reduce **intracellular sodium** and subsequent calcium overload, rather than opening K+ channels. *Verapamil* - **Verapamil** is a **non-dihydropyridine calcium channel blocker**. - It works by inhibiting the influx of calcium into cardiac and smooth muscle cells, thus decreasing contractility and causing vasodilation, not by opening K+ channels. *Lignocaine* - **Lignocaine** (lidocaine) is a **sodium channel blocker** primarily used as a local anesthetic and antiarrhythmic. - It stabilizes neuronal and cardiac cell membranes by preventing sodium influx, which differs from K+ channel modulation.

Q: Which one of the following was traditionally considered the drug of choice for ventricular tachycardia in myocardial infarction?

Xylocaine. ***Xylocaine/Lidocaine*** - **Lidocaine (Xylocaine)** is a **Class IB antiarrhythmic drug** [2] that was historically the drug of choice for suppressing ventricular arrhythmias, including ventricular tachycardia, in the setting of **myocardial ischemia and infarction** [1]. - It works by **blocking sodium channels** and shortening the action potential duration, thereby reducing excitability and automaticity in ischemic myocardial tissue [1]. - **Current guidelines**: Lidocaine is now considered a **second-line agent**, with **amiodarone** being the preferred first-line antiarrhythmic for hemodynamically stable VT in acute MI, and electrical cardioversion for unstable VT. *Digitalis* - **Digitalis** (e.g., digoxin) is primarily used for **supraventricular arrhythmias** like atrial fibrillation or flutter, and for heart failure due to its positive inotropic effect. - It can **aggravate ventricular arrhythmias** in the setting of acute myocardial infarction and is generally contraindicated for ventricular tachycardia. *Quinidine* - **Quinidine** is a **Class IA antiarrhythmic drug** that prolongs the action potential and is effective against a variety of arrhythmias. - However, it can cause **hypotension** and has a **proarrhythmic effect**, increasing the risk of Torsades de Pointes, making it less favorable as a first-line agent, especially in acute MI. *Disopyramide* - **Disopyramide** is also a **Class IA antiarrhythmic drug** with similar mechanisms to quinidine. - It has significant **negative inotropic effects** and can worsen heart failure [3], which is a common complication in acute myocardial infarction, making it less suitable.

Q: Which of the following antiarrhythmic drugs is contraindicated in a patient with interstitial lung disease?

Amiodarone. ***Amiodarone*** - **Amiodarone** is contraindicated in patients with interstitial lung disease due to its well-known and potentially severe pulmonary toxicity, which can exacerbate or induce **pulmonary fibrosis**. - Its long half-life means that drug accumulation and persistent adverse effects, including **ILD exacerbation**, are significant concerns. *Sotalol* - **Sotalol** primarily carries risks of **prolonged QT interval** and **torsades de pointes** because it has both beta-blocking and Class III antiarrhythmic properties. - While it has cardiac and minor non-cardiac side effects, it is not specifically known to cause or worsen **interstitial lung disease**. *Lignocaine* - **Lignocaine** (lidocaine) is a Class Ib antiarrhythmic primarily used for **ventricular arrhythmias**, especially in acute settings. - Its adverse effects are mainly **neurological** (e.g., dizziness, seizures at high doses) and **cardiovascular** (e.g., hypotension, bradycardia), with no significant association with lung disease. *Quinidine* - **Quinidine** is a Class Ia antiarrhythmic that can cause a variety of side effects, including **gastrointestinal upset**, **cinchonism** (tinnitus, blurred vision), and **cardiac rhythm disturbances**. - While it can rarely cause a hypersensitivity pneumonitis, it is not a primary concern or contraindication in existing **interstitial lung disease** compared to amiodarone.

Q: In which of the following conditions is digoxin most likely to accumulate to toxic levels?

Renal insufficiency. ***Renal insufficiency*** - **Digoxin** is primarily excreted unchanged by the **kidneys**, so impaired renal function significantly prolongs its half-life and leads to drug accumulation. - Patients with kidney failure require **dose adjustments** or closer monitoring of **digoxin levels** to prevent toxicity. *Chronic hepatitis* - **Chronic hepatitis** primarily affects the **liver's metabolic capacity**, which is not the primary route of **digoxin elimination**. - While severe hepatic dysfunction can subtly impact drug disposition, it's not the main reason for **digoxin accumulation** like **renal insufficiency**. *Advanced cirrhosis* - **Advanced cirrhosis** involves severe liver dysfunction, which can alter drug metabolism and protein binding. - However, **digoxin's elimination** is mainly renal, so liver disease alone does not typically lead to significant accumulation unless accompanied by **renal impairment**. *Chronic pancreatitis* - **Chronic pancreatitis** is a disorder of the pancreas and does not directly impact the **excretion or metabolism** of **digoxin**. - It would not be expected to cause **digoxin accumulation** to toxic levels.

Q: Which of the following vitamins can be used in high doses to treat hypercholesterolemia?

Niacin. ***Niacin*** - **Niacin** (Vitamin B3) in pharmacological doses effectively lowers **LDL cholesterol** and triglycerides while raising **HDL cholesterol**. - Its mechanism involves inhibiting **hepatic VLDL secretion** and decreasing the catabolism of **HDL**. *Vitamin B2* - **Vitamin B2** (riboflavin) is crucial for **cellular energy production** and acts as a cofactor in various enzyme reactions. - It does not have a significant role in **lipid metabolism** or in treating **hypercholesterolemia** at high doses. *Vitamin B5* - **Vitamin B5** (pantothenic acid) is a component of **coenzyme A**, essential for **fatty acid synthesis** and breakdown. - While involved in metabolism, it is not used therapeutically to manage **hypercholesterolemia**. *Vitamin B1* - **Vitamin B1** (thiamine) is vital for **carbohydrate metabolism** and **nerve function**. - There is no evidence supporting its use in treating **hypercholesterolemia**.

Question 1

BETA-blockers are contraindicated in which of the following conditions?

Accepted Answer

Variant angina

Answer

Hypertension

Answer

Thyrotoxicosis

Answer

None of the options

Question 2

All the following statements regarding adenosine are true except:

Accepted Answer

Administered by slow I.V. injection

Answer

Dipyridamole potentiates its action

Answer

Administered by rapid I.V. injection

Answer

Used in the treatment of supraventricular tachycardia

Question 3

Nitrates decrease myocardial oxygen consumption by all of the following mechanisms except which of the following?

Accepted Answer

By increasing the left ventricular end diastolic pressure

Answer

By dilation of the capacitance vessels

Answer

By direct reduction of oxygen consumption of the myocardial cell

Answer

By decreasing the size of the heart

Question 4

Which of the following antihypertensive drugs is avoided in patients with high serum uric acid levels?

Accepted Answer

Hydrochlorothiazide

Answer

Enalapril

Answer

Prazosin

Answer

Atenolol

Question 5

Which of the following is the best inotrope agent for use in right heart failure secondary to pulmonary hypertension?

Accepted Answer

Milrinone

Answer

Dobutamine

Answer

Digoxin

Answer

Dopamine

Question 6

Which of the following is a K+ channel opener?

Accepted Answer

Nicorandil

Answer

Ranolazine

Answer

Verapamil

Answer

Lignocaine

Question 7

Which one of the following was traditionally considered the drug of choice for ventricular tachycardia in myocardial infarction?

Accepted Answer

Xylocaine

Answer

Digitalis

Answer

Quinidine

Answer

Disopyramide

Question 8

Which of the following antiarrhythmic drugs is contraindicated in a patient with interstitial lung disease?

Accepted Answer

Amiodarone

Answer

Lignocaine

Answer

Sotalol

Answer

Quinidine

Question 9

In which of the following conditions is digoxin most likely to accumulate to toxic levels?

Accepted Answer

Renal insufficiency

Answer

Chronic hepatitis

Answer

Advanced cirrhosis

Answer

Chronic pancreatitis

Question 10

Which of the following vitamins can be used in high doses to treat hypercholesterolemia?

Accepted Answer

Niacin

Answer

Vitamin B2

Answer

Vitamin B5

Answer

Vitamin B1

Cardiovascular Drugs — MCQs

Cardiovascular Drugs — MCQs

On this page

Practice by Chapter

Want unlimited practice?