Antianginal Agents — MCQs
The following smooth muscle relaxants act by affecting calcium release except:
Which of the following agents is not used to provide induced hypotension during surgery ?
Which of the following is a late inward sodium channel blocker?
Which of the following drugs lack vasodilatory properties but are effective in angina?
Nitrates can be used for all of the following conditions except:
Duration of pain in angina is:
A 55-year-old male, known smoker, complains of calf pain while walking. He experiences calf pain while walking but can continue walking with effort. Which grade of claudication does this patient fall under?
Match the following drugs in Column A with their contraindications in Column B. | Column A | Column B | | :-- | :-- | | 1. Morphine | 1. QT prolongation | | 2. Amiodarone | 2. Thromboembolism | | 3. Vigabatrin | 3. Pregnancy | | 4. Estrogen preparations | 4. Head injury |
Which of the following is a contraindication to the use of beta-blockers?
A 35-year-old with migraines needs prophylaxis. Which is suitable?
Antianginal Agents Indian Medical PG Practice Questions and MCQs
Question 1: The following smooth muscle relaxants act by affecting calcium release except:
- A. Dantrolene
- B. Nifedipine
- C. Prazosin (Correct Answer)
- D. Verapamil
Explanation: ***Prazosin*** - Prazosin is an **alpha-1 adrenergic receptor antagonist** that causes smooth muscle relaxation by blocking the vasoconstrictive effects of norepinephrine, **not by directly affecting calcium release or calcium channels** [4]. - Its mechanism involves preventing receptor-mediated vasoconstriction through downstream signaling pathways, which are distinct from direct calcium channel modulation or calcium release from intracellular stores. - **This is the correct answer** as it does not act by affecting calcium handling. *Dantrolene* - Dantrolene acts by inhibiting the release of **calcium from the sarcoplasmic reticulum** in muscle cells by blocking **ryanodine receptors (RyR1)**. - **Important note:** Dantrolene is primarily a **skeletal muscle relaxant** used for malignant hyperthermia and spasticity, not a typical smooth muscle relaxant. - While it does affect calcium release, its primary therapeutic action is on skeletal muscle, making its inclusion in "smooth muscle relaxants" questionable. *Nifedipine* - Nifedipine is a **dihydropyridine calcium channel blocker** that inhibits the influx of extracellular calcium into smooth muscle cells [2]. - By blocking **L-type voltage-gated calcium channels**, it reduces intracellular calcium availability, leading to smooth muscle relaxation, particularly in vascular smooth muscle [1], [3]. *Verapamil* - Verapamil is a **non-dihydropyridine calcium channel blocker** that also inhibits the influx of extracellular calcium into smooth muscle cells [3]. - It primarily affects **L-type calcium channels** in both cardiac and smooth muscle, leading to vasodilation and reduced cardiac contractility [1], [2].
Question 2: Which of the following agents is not used to provide induced hypotension during surgery ?
- A. Mephenteramine (Correct Answer)
- B. Sodium nitroprusside
- C. Hydralazine
- D. Esmolol
Explanation: ***Mephenteramine*** - **Mephentermine** is a **vasopressor** used to **increase blood pressure**, acting primarily through the release of **norepinephrine**. - Its effects are opposite to what is desired for **induced hypotension** during surgery, as the goal is to lower systemic blood pressure to reduce blood loss and improve surgical field visibility. *Sodium nitroprusside* - **Sodium nitroprusside** is a potent **vasodilator** that directly relaxes both **arterial** and **venous smooth muscle**, leading to a rapid and significant decrease in blood pressure. - Its rapid onset and offset of action make it a valuable agent for **controlled induced hypotension** during surgery. *Hydralazine* - **Hydralazine** is a **direct-acting arterial vasodilator** that primarily relaxes arterial smooth muscle, leading to a decrease in **peripheral vascular resistance** and blood pressure. - It can be used to induce or maintain **hypotension** during surgery, although its onset of action is slower compared to nitroprusside. *Esmolol* - **Esmolol** is a **short-acting beta-1 selective adrenergic blocker** that reduces heart rate and myocardial contractility, thereby decreasing cardiac output. - By reducing cardiac output, esmolol can contribute to **induced hypotension**, often used in conjunction with vasodilators or in situations where controlling heart rate is also desired.
Question 3: Which of the following is a late inward sodium channel blocker?
- A. Ranolazine (Correct Answer)
- B. Fasudil
- C. Ivabradine
- D. Trimetazidine
Explanation: ***Ranolazine*** - **Ranolazine** selectively inhibits the **late inward sodium current (I_Na)** in cardiac myocytes. - By reducing this current, it helps to decrease intracellular **sodium and calcium overload**, thereby improving myocardial relaxation and reducing angina and ischemia. *Ivabradine* - **Ivabradine** is a selective **funny channel (If) inhibitor** in the sinoatrial node. - It slows down the heart rate by reducing the rate of diastolic depolarization, primarily used for **chronic stable angina** and **heart failure**. *Fasudil* - **Fasudil** is a **rho-kinase inhibitor** used primarily in Japan and China for **cerebral vasospasm** following subarachnoid hemorrhage. - It works by inhibiting the phosphorylation of myosin light chain, leading to **vasodilation**. *Trimetazidine* - **Trimetazidine** is an **anti-ischemic metabolic agent** that inhibits the enzyme 3-ketoacyl-CoA thiolase, shifting cardiac metabolism from fatty acid oxidation to glucose oxidation. - This improves myocardial glucose utilization, which is more efficient in **ischemic conditions**, thereby reducing angina symptoms.
Question 4: Which of the following drugs lack vasodilatory properties but are effective in angina?
- A. Metoprolol (Correct Answer)
- B. Isosorbide dinitrate
- C. Nifedipine
- D. Verapamil
Explanation: ***Metoprolol*** - **Metoprolol** is a beta-blocker that reduces myocardial oxygen demand by decreasing heart rate, contractility, and blood pressure, without direct vasodilatory effects. - Its efficacy in angina is primarily due to these **cardiac depressant actions**, which relieve myocardial ischemia. *Isosorbide dinitrate* - **Isosorbide dinitrate** is a nitrate that works by releasing nitric oxide, leading to **venodilation** and **arterial dilation**, particularly reducing preload and improving coronary blood flow. - Its anti-anginal effect is directly linked to its **vasodilatory properties**. *Nifedipine* - **Nifedipine** is a dihydropyridine calcium channel blocker that produces potent **vasodilation** of both coronary and peripheral arteries. - Its primary mechanism of action in angina involves **reducing afterload** and improving coronary blood flow through vasodilation. *Verapamil* - **Verapamil** is a non-dihydropyridine calcium channel blocker that causes **coronary and peripheral vasodilation**, reducing afterload and improving myocardial perfusion. - While it also reduces heart rate and contractility, its direct **vasodilatory effects** contribute significantly to its anti-anginal action.
Question 5: Nitrates can be used for all of the following conditions except:
- A. Esophageal spasm
- B. Congestive heart failure
- C. Renal colic
- D. Cyanide poisoning (Correct Answer)
Explanation: ***Cyanide poisoning*** - This is the correct answer because **organic nitrates** (nitroglycerin, isosorbide dinitrate) used in cardiovascular practice are **not indicated** for cyanide poisoning. - While **nitrites** (amyl nitrite, sodium nitrite) - different compounds - can induce methemoglobinemia to bind cyanide, these are not the same as the organic nitrates used for cardiovascular conditions. - Current primary treatment for cyanide poisoning uses **hydroxocobalamin** and **sodium thiosulfate**, not cardiovascular nitrate preparations. *Congestive heart failure* - Nitrates cause **venodilation**, which reduces **preload** on the heart, thereby decreasing myocardial wall stress and oxygen demand. - This effect is beneficial in **acute decompensated heart failure** to manage symptoms like pulmonary congestion and dyspnea. - Commonly used preparations include IV nitroglycerin and sublingual nitroglycerin for acute management. *Esophageal spasm* - Nitrates relax **smooth muscle**, including the smooth muscle of the esophagus. - This property makes them useful in relieving the pain and discomfort associated with **diffuse esophageal spasm**. - Sublingual nitroglycerin can provide symptomatic relief. *Renal colic* - Nitrates cause **smooth muscle relaxation**, which can help to dilate the **ureters**. - This dilation can facilitate the passage of kidney stones and alleviate the severe pain associated with **renal colic**. - Though NSAIDs are first-line, nitrates may be used adjunctively for smooth muscle relaxation.
Question 6: Duration of pain in angina is:
- A. 2-5 mins (Correct Answer)
- B. 5-30 mins
- C. 30-60 mins
- D. > 1 hour
Explanation: **2-5 mins** - **Stable angina** chest pain typically lasts for a few minutes, usually 2 to 5 minutes, and is precipitated by exertion or stress [1]. - Pain is **relieved by rest** or nitroglycerin within minutes [1]. *5-30 mins* - This duration is longer than typical stable angina and could indicate **unstable angina** or another cardiac event, requiring immediate medical evaluation [1]. - While an myocardial infarction (MI) is a possibility, pain lasting this specific duration is not the hallmark of stable angina [1]. *30-60 mins* - This duration is characteristic of prolonged cardiac ischemia, such as an **acute myocardial infarction (heart attack)**, rather than stable angina [1]. - Such prolonged pain signals serious heart damage and requires urgent medical intervention [2]. *> 1 hour* - Pain lasting over an hour is atypical for angina and strongly suggests an **acute myocardial infarction (MI)** or other non-cardiac causes like pericarditis or aortic dissection. - **Angina pain is generally brief** and resolves quickly [1].
Question 7: A 55-year-old male, known smoker, complains of calf pain while walking. He experiences calf pain while walking but can continue walking with effort. Which grade of claudication does this patient fall under?
- A. Grade I (Mild claudication)
- B. Grade II (Moderate claudication) (Correct Answer)
- C. Grade III (Severe claudication)
- D. Grade IV (Ischemic rest pain)
Explanation: ***Grade II (Moderate claudication)*** - **Grade II claudication** is characterized by **intermittent claudication** where the patient experiences pain while walking but can **continue walking with effort**. - This level of claudication reflects a moderate degree of peripheral arterial disease, where blood flow is sufficiently compromised to cause pain with exertion but not severe enough to force immediate cessation of activity. - The patient in this scenario can continue ambulation despite discomfort, which is the defining feature of this grade. *Grade I (Mild claudication)* - **Grade I claudication** involves discomfort or pain that the patient can **tolerate without significantly altering their gait or pace**. - In this stage, the pain is minimal, and the patient may perceive it as a dull ache or mild fatigue rather than true pain. - Walking can continue without significant effort or limitation. *Grade III (Severe claudication)* - **Grade III claudication** is marked by pain that is **severe enough to stop the patient from walking within a short distance** (typically less than 200 meters). - The pain forces the patient to rest and recover before they can resume walking. - This represents significant functional limitation in daily activities. *Grade IV (Ischemic rest pain)* - **Grade IV**, also known as **critical limb ischemia**, involves **pain even at rest**, especially in the feet or toes, often worsening at night when the limb is elevated. - This stage indicates severe arterial obstruction and is frequently associated with **ulcers, non-healing wounds, or gangrene**. - This represents advanced peripheral arterial disease requiring urgent intervention. **Note:** This grading system is a simplified clinical classification. The standard medical classifications for peripheral arterial disease are the **Fontaine classification** (Stages I-IV) and **Rutherford classification** (Categories 0-6).
Question 8: Match the following drugs in Column A with their contraindications in Column B. | Column A | Column B | | :-- | :-- | | 1. Morphine | 1. QT prolongation | | 2. Amiodarone | 2. Thromboembolism | | 3. Vigabatrin | 3. Pregnancy | | 4. Estrogen preparations | 4. Head injury |
- A. A-1, B-3, C-2, D-4
- B. A-4, B-1, C-3, D-2 (Correct Answer)
- C. A-3, B-2, C-4, D-1
- D. A-2, B-4, C-1, D-3
Explanation: ***A-4, B-1, C-3, D-2*** - **Morphine** is contraindicated in **head injury** as it can increase intracranial pressure and mask neurological symptoms. - **Amiodarone** is contraindicated in patients with **QT prolongation** due to its risk of inducing more severe arrhythmias like Torsades de Pointes. - **Vigabatrin** is contraindicated during **pregnancy** due to its potential for teratogenicity and adverse effects on fetal development. - **Estrogen preparations** are contraindicated in patients with a history of **thromboembolism** due to their increased risk of blood clot formation. *A-1, B-3, C-2, D-4* - This option incorrectly matches **Morphine** with QT prolongation and **Estrogen preparations** with head injury, which are not their primary contraindications. - It also incorrectly links **Vigabatrin** with thromboembolism and **Amiodarone** with pregnancy. *A-3, B-2, C-4, D-1* - This choice incorrectly associates **Morphine** with pregnancy and **Vigabatrin** with head injury, which are not the most critical or direct contraindications. - It also misaligns **Amiodarone** with thromboembolism and **Estrogen preparations** with QT prolongation. *A-2, B-4, C-1, D-3* - This option incorrectly matches **Morphine** with thromboembolism and **Amiodarone** with head injury, which are not their most significant contraindications. - It also incorrectly links **Vigabatrin** with QT prolongation and **Estrogen preparations** with pregnancy.
Question 9: Which of the following is a contraindication to the use of beta-blockers?
- A. Glaucoma
- B. Tachycardia
- C. Hypertension
- D. Bronchial asthma (Correct Answer)
Explanation: ***Bronchial asthma*** - Beta-blockers, especially non-selective ones, can cause **bronchoconstriction** by blocking beta-2 receptors in the lungs, worsening asthma symptoms. - This can precipitate an **asthma exacerbation** or severe respiratory distress in susceptible individuals. *Glaucoma* - Beta-blockers are actually used in the treatment of glaucoma, as they **decrease aqueous humor production**, thereby lowering intraocular pressure. - Thus, it is a **therapeutic indication**, not a contraindication. *Tachycardia* - Beta-blockers are frequently used to treat various forms of tachycardia by **slowing the heart rate** and reducing myocardial oxygen demand. - They achieve this by blocking beta-1 receptors in the heart, making tachycardia an **indication** rather than a contraindication. *Hypertension* - Beta-blockers are a well-established class of drugs for the treatment of hypertension, as they **reduce blood pressure** by various mechanisms, including decreasing heart rate and cardiac output. - Therefore, hypertension is an **indication** for beta-blocker use, not a contraindication.
Question 10: A 35-year-old with migraines needs prophylaxis. Which is suitable?
- A. Acetaminophen
- B. Sumatriptan
- C. Verapamil (Correct Answer)
- D. Tramadol
Explanation: ***Verapamil*** - **Verapamil**, a calcium channel blocker, is often used off-label for **migraine prophylaxis**, particularly in cases where other first-line agents are contraindicated or ineffective. - While not a first-line treatment, it can reduce the frequency and severity of migraine attacks by modulating **vasoconstriction** and **vasodilation**. *Acetaminophen* - **Acetaminophen** is an analgesic used for **acute pain relief**, but it does not have properties that prevent migraine attacks from occurring. - It is unsuitable for long-term **prophylactic management** of migraines. *Sumatriptan* - **Sumatriptan** is a **triptan** medication used for **acute migraine treatment**, meaning it is taken to stop a migraine attack once it has started. - It is not indicated for **migraine prophylaxis** and should not be used regularly to prevent migraines. *Tramadol* - **Tramadol** is an **opioid analgesic** used for moderate to severe pain, and it carries risks of dependence and side effects. - It is not recommended for **migraine prophylaxis** due to its addictive potential and lack of evidence for preventing migraine attacks.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free