NEET-PG 2013 Practice Questions

Q: What is the most appropriate initial management for paralysis resulting from organophosphorus poisoning?

Supportive care, including respiratory support. **Supportive care, including respiratory support** * **Paralysis** in organophosphorus poisoning (OPP) is often due to **nicotinic effects** at the neuromuscular junction, leading to respiratory muscle weakness and failure [2]. * **Respiratory support** through mechanical ventilation is crucial to maintain oxygenation and prevent complications while awaiting the effects of antidotal therapy [1], [2]. * *Atropine to counteract muscarinic symptoms* * **Atropine** primarily blocks **muscarinic receptors**, effectively treating symptoms like bradycardia, bronchorrhea, and miosis [2]. * It does **not reverse the nicotinic effects** responsible for muscle paralysis and respiratory failure. * *Oximes to reactivate acetylcholinesterase* * **Oximes (e.g., pralidoxime)** reactivate **acetylcholinesterase**, thereby addressing the underlying cause of acetylcholine accumulation [2]. * They are most effective if given **early** before irreversible aging of the enzyme occurs, but their effect on established paralysis can be limited without concurrent respiratory support [2]. * *No specific antidote* * This statement is incorrect; **atropine** and **oximes** are specific antidotes for organophosphorus poisoning [2]. * While these antidotes are vital, initial management prioritizing **airway and breathing support** is paramount due to the life-threatening respiratory paralysis [1].

Q: Which of the following statements is true regarding light microscopy findings in minimal change disease?

No significant changes are seen under light microscopy.. ***No change seen*** - In minimal change disease, **light microscopy** typically shows no significant changes, which is a key characteristic of the condition [1]. - The disease primarily affects the **podocytes** leading to **nephrotic syndrome**, while light microscopy does not reveal any abnormalities [1]. *Loss of foot process seen* - Loss of foot processes is actually observed under **electron microscopy**, not light microscopy. - Light microscopy remains normal, differentiating minimal change disease from other glomerular diseases. *IgA deposits seen* - IgA deposits are associated with **IgA nephropathy**, which is a different condition characterized by mesangial deposition. - Minimal change disease does not have **immunofluorescence** findings, and thus shows no such deposits on light microscopy [1]. *Anti GBM Abs seen* - Anti-GBM antibodies are characteristic of **Goodpasture syndrome**, which presents with significant changes in glomerular structure. - In minimal change disease, there are no **anti-GBM antibodies** or major changes visible under light microscopy. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 927-928.

Q: Which beta-1 antagonist is used in congestive cardiac failure?

Metoprolol. ***Metoprolol*** - **Metoprolol succinate** (extended-release formulation) is a selective **beta-1 antagonist** proven to reduce mortality and hospitalizations in **chronic heart failure with reduced ejection fraction (HFrEF)**. - It works by **reducing heart rate, myocardial oxygen demand**, and preventing adverse cardiac remodeling through inhibition of chronic sympathetic activation. - Along with **bisoprolol and carvedilol**, it is one of the **three beta-blockers with proven mortality benefit** in heart failure trials. *Atenolol* - While atenolol is a selective beta-1 antagonist, it **lacks evidence for mortality benefit** in heart failure. - It has **high hydrophilicity** and renal elimination, leading to less favorable pharmacokinetics compared to metoprolol. - More commonly used for **hypertension and angina** rather than heart failure management. *Esmolol* - **Esmolol** is an ultra-short-acting selective beta-1 antagonist used for **acute control of heart rate** in perioperative and critical care settings. - Its **very short half-life (9 minutes)** makes it unsuitable for chronic management of heart failure. - Administered only **intravenously** and requires continuous infusion. *Bisoprolol* - While **bisoprolol is also approved** for heart failure and has proven mortality benefit (CIBIS-II trial), this question likely expects **metoprolol** as the answer given the historical context. - Both bisoprolol and metoprolol are acceptable answers, but **metoprolol** has been more widely studied and is more commonly cited in Indian medical exams. - Bisoprolol has **greater beta-1 selectivity** than metoprolol but similar clinical outcomes in heart failure.

Q: Which urinary bladder spasmolytic has local anesthetic properties?

Oxybutynin. ***Oxybutynin*** - Possesses both **anticholinergic properties** (bladder smooth muscle relaxation) and **direct local anesthetic properties**, which contribute to its spasmolytic effect on the detrusor muscle. - The **local anesthetic action** directly reduces bladder detrusor muscle contractions, explaining its efficacy in treating urge incontinence and overactive bladder. - This dual mechanism makes it unique among bladder spasmolytics. *Tamsulosin* - Is an **alpha-1 adrenergic receptor blocker** used for benign prostatic hyperplasia (BPH) by relaxing smooth muscle in the prostate and bladder neck. - Does **not have local anesthetic properties** and is not a bladder detrusor spasmolytic. *Terazosin* - Also an **alpha-1 adrenergic receptor blocker**, similar to tamsulosin, used for BPH and hypertension. - Acts via **vascular and prostatic smooth muscle relaxation**, without local anesthetic or bladder spasmolytic effects. *Yohimbine* - Is an **alpha-2 adrenergic receptor antagonist** known for increasing sympathetic outflow. - Does **not have bladder spasmolytic effects** or local anesthetic properties.

Q: Which antiglaucomatous drug is known to cause spasm of accommodation?

Pilocarpine. ***Pilocarpine*** - **Pilocarpine** is a **direct-acting muscarinic agonist** that contracts the **ciliary muscle**. - Contraction of the ciliary muscle leads to **accommodation spasm** and a forward movement of the **iris-lens diaphragm**, which also helps to open the **trabecular meshwork**, facilitating aqueous outflow. *Timolol* - **Timolol** is a **beta-blocker** that reduces aqueous humor production by blocking beta-adrenergic receptors on the ciliary epithelium. - It does not directly affect the **ciliary muscle** or cause accommodation spasm. *Dorazolamide* - **Dorzolamide** is a **carbonic anhydrase inhibitor** that reduces aqueous humor production. - Its mechanism of action does not involve the ciliary body's mechanical action and therefore does not cause **accommodation spasm**. *Latanoprost* - **Latanoprost** is a **prostaglandin analog** that increases uveoscleral outflow of aqueous humor. - It does not directly affect the ciliary muscle's contraction or cause **accommodation spasm**.

Q: Which of the following is not a cardioselective beta blocker?

Oxprenolol. ***Oxprenolol*** - **Oxprenolol** is a non-selective beta-blocker with **intrinsic sympathomimetic activity (ISA)**, meaning it blocks both β1 and β2 receptors and partially stimulates them. - Its non-selective action means it affects both the heart (β1) and other organs like the lungs (β2), making it less suitable for patients with respiratory conditions. *Nebivolol* - **Nebivolol** is a highly cardioselective beta-blocker that primarily blocks **β1 receptors** and also has **vasodilatory properties** due to nitric oxide release. - Its high selectivity translates to fewer β2-mediated side effects, such as bronchoconstriction. *Atenolol* - **Atenolol** is a **cardioselective beta-blocker** that predominantly blocks **β1 receptors** at therapeutic doses. - This selectivity makes it a common choice for cardiovascular conditions, reducing the risk of bronchospasm compared to non-selective agents. *Betaxolol* - **Betaxolol** is a **cardioselective beta-blocker** primarily used for the treatment of hypertension and glaucoma. - It selectively blocks **β1 adrenergic receptors**, minimizing effects on the lungs compared to non-selective beta-blockers.

Q: Muscarinic cholinergic receptors are seen at all sites, except?

Neuromuscular junction. ***Neuromuscular junction*** - The **neuromuscular junction** primarily contains **nicotinic cholinergic receptors**, not muscarinic receptors. - Activation of these nicotinic receptors by acetylcholine causes muscle contraction. *Stomach* - The stomach contains **muscarinic M3 receptors** which mediate gastric acid secretion and smooth muscle contraction. - Activation by acetylcholine via the vagus nerve promotes digestion. *CNS* - The **central nervous system** has various subtypes of **muscarinic receptors (M1-M5)** distributed throughout, playing roles in learning, memory, and motor control. - These receptors modulate neuronal excitability and neurotransmitter release. *Glands* - Most exocrine glands (e.g., salivary, lacrimal, sweat glands) are richly supplied with **muscarinic receptors**, primarily **M3**. - Activation leads to increased glandular secretion.

Q: Which of the following is classified as an antispasmodic agent?

Dicyclomine. ***Dicyclomine*** - **Dicyclomine** is an **anticholinergic** medication that works by blocking muscarinic receptors, thereby reducing smooth muscle spasm in the gastrointestinal tract. - It is commonly used to treat symptoms of **irritable bowel syndrome (IBS)**, such as abdominal pain and cramping. *Physostigmine* - **Physostigmine** is a **cholinesterase inhibitor** that increases the concentration of acetylcholine at the synaptic cleft. - It is used to treat **anticholinergic poisoning** by reversing the effects of anticholinergic drugs, rather than acting as an antispasmodic itself. *Tropicamide* - **Tropicamide** is an **anticholinergic** agent primarily used as a **mydriatic** (pupil dilator) and **cycloplegic** (paralyzes the ciliary muscle) for ophthalmic examinations. - Its action is localized to the eye and it does not have significant systemic antispasmodic effects. *None of the options* - This option is incorrect because one of the listed medications is indeed classified as an antispasmodic agent. - When "None of the options" appears as a choice, it should only be selected if all other options are clearly incorrect.

Q: Besides its properties of decreasing intraocular pressure, timolol is preferred in the treatment of glaucoma because it

Produces no miosis. ***Produces no miosis*** - Timolol, a **non-selective beta-blocker**, decreases intraocular pressure without affecting pupillary size. - This is a **key advantage** in glaucoma treatment as miosis (pupil constriction) can worsen vision, especially in patients with cataracts. - Unlike **miotics** (e.g., pilocarpine), timolol does not cause pupillary constriction, making it better tolerated. *Possesses membrane stabilizing activity* - While some beta-blockers possess **membrane-stabilizing activity** (local anesthetic effect), this property is not a primary reason for timolol's preference in glaucoma. - This action is more relevant in antiarrhythmic uses of beta-blockers due to its effect on cardiac action potentials. *Increases outflow of aqueous humor* - Timolol primarily reduces intraocular pressure by **decreasing the production of aqueous humor**, not by increasing its outflow. - Drugs like **pilocarpine** (a cholinergic agonist) or **prostaglandin analogs** increase outflow. *Is a selective beta-adrenoceptor blocker* - Timolol is a **non-selective beta-blocker**, meaning it blocks both beta-1 and beta-2 adrenergic receptors. - Its non-selectivity is associated with systemic side effects (e.g., bronchospasm, bradycardia), and selective beta-blockers like **betaxolol** exist but are not the primary reason for timolol's preference in glaucoma.

Q: Which of the following is not a recognized use of alpha-2-agonists?

Benign Hyperplasia of prostate. ***Correct Answer: Benign Hyperplasia of prostate*** - Alpha-2-agonists are **NOT** used to treat **benign prostatic hyperplasia (BPH)**; this condition is typically managed with **alpha-1-blockers** (e.g., tamsulosin, alfuzosin) or 5-alpha-reductase inhibitors. - Alpha-1-blockers relax the smooth muscle in the prostate and bladder neck, improving urine flow, which involves a different receptor mechanism than alpha-2-agonists. - Alpha-2-agonists would not provide therapeutic benefit for BPH. *Incorrect: Glaucoma* - Alpha-2-agonists (e.g., **brimonidine**, **apraclonidine**) **are** used to treat **glaucoma** by reducing aqueous humor production and increasing uveoscleral outflow. - This action helps to **lower intraocular pressure**, a primary goal in glaucoma management. *Incorrect: Hypertension* - Central-acting alpha-2-agonists (e.g., **clonidine**, **methyldopa**) **are** used as **antihypertensive agents**. - They reduce sympathetic outflow from the central nervous system, leading to decreased heart rate, vasodilation, and consequently, **lower blood pressure**. *Incorrect: Sedation* - Alpha-2-agonists like **dexmedetomidine** and **clonidine** **are** commonly used for **sedation** in critically ill patients, especially in intensive care units. - They produce sedation, analgesia, and anxiolysis without causing significant respiratory depression, making them valuable in certain clinical settings.

Question 1

What is the most appropriate initial management for paralysis resulting from organophosphorus poisoning?

Accepted Answer

Supportive care, including respiratory support

Answer

Atropine to counteract muscarinic symptoms

Answer

Oximes to reactivate acetylcholinesterase

Answer

No specific antidote

Question 2

Which of the following statements is true regarding light microscopy findings in minimal change disease?

Accepted Answer

No significant changes are seen under light microscopy.

Answer

Foot process effacement is observed under electron microscopy, not light microscopy.

Answer

Anti-GBM antibodies are associated with Goodpasture syndrome, not minimal change disease.

Answer

IgA deposits are characteristic of IgA nephropathy, not minimal change disease.

Question 3

Which beta-1 antagonist is used in congestive cardiac failure?

Accepted Answer

Metoprolol

Answer

Atenolol

Answer

Esmolol

Answer

Bisoprolol

Question 4

Which urinary bladder spasmolytic has local anesthetic properties?

Accepted Answer

Oxybutynin

Answer

Tamsulosin

Answer

Terazosin

Answer

Yohimbine

Question 5

Which antiglaucomatous drug is known to cause spasm of accommodation?

Accepted Answer

Pilocarpine

Answer

Timolol

Answer

Dorzolamide

Answer

Latanoprost

Question 6

Which of the following is not a cardioselective beta blocker?

Accepted Answer

Oxprenolol

Answer

Nebivolol

Answer

Atenolol

Answer

Betaxolol

Question 7

Muscarinic cholinergic receptors are seen at all sites, except?

Accepted Answer

Neuromuscular junction

Answer

Stomach

Answer

CNS

Answer

Glands

Question 8

Which of the following is classified as an antispasmodic agent?

Accepted Answer

Dicyclomine

Answer

Physostigmine

Answer

Tropicamide

Answer

None of the options

Question 9

Besides its properties of decreasing intraocular pressure, timolol is preferred in the treatment of glaucoma because it

Accepted Answer

Produces no miosis

Answer

Is a selective beta-adrenoceptor blocker

Answer

Increases outflow of aqueous humor

Answer

Possesses membrane stabilizing activity

Question 10

Which of the following is not a recognized use of alpha-2-agonists?

Accepted Answer

Benign Hyperplasia of prostate

Answer

Glaucoma

Answer

Hypertension

Answer

Sedation

NEET-PG 2013

Internal Medicine

Pathology

Pharmacology