NEET-PG 2012 - Pharmacology Practice Questions

Q: Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?

Beta-2 receptor stimulation. ***Beta-2 receptor stimulation*** - Theophylline is a **non-selective phosphodiesterase inhibitor** and an **adenosine receptor antagonist**, but it does not directly stimulate beta-2 receptors. - **Beta-2 receptor agonists** like salbutamol or formoterol are the medications that work by stimulating these receptors to cause bronchodilation. *Phosphodiesterase inhibition* - Theophylline inhibits **phosphodiesterase enzymes**, leading to an increase in intracellular **cAMP** levels. - This increase in **cAMP** promotes bronchodilation by relaxing airway smooth muscle. *Adenosine receptor antagonism* - Theophylline acts as an antagonist at **adenosine receptors**, particularly A1 and A2B. - Antagonism of adenosine receptors can reduce bronchoconstriction and inflammatory mediator release, contributing to its anti-asthmatic effects. *Increased histone deacetylation* - Theophylline, particularly at lower concentrations, increases the activity of **histone deacetylase (HDAC)**. - This action helps to **repress inflammatory gene expression**, which is a unique anti-inflammatory mechanism separate from its bronchodilatory effects.

Q: Omalizumab is primarily used in the treatment of which condition?

Asthma. ***Asthma*** - **Omalizumab** is a **monoclonal antibody** that targets and binds to **immunoglobulin E (IgE)**, preventing it from binding to mast cells and basophils. - By reducing free IgE, omalizumab helps to prevent the release of inflammatory mediators, thereby **reducing allergic reactions and asthma symptoms**, particularly in patients with severe persistent allergic asthma. *Breast carcinoma* - **Omalizumab** is not indicated for the treatment of **breast carcinoma**; treatments for breast cancer typically involve chemotherapy, radiation, surgery, and targeted therapies specific to cancer cells. - Targeted therapies for breast cancer often focus on hormone receptors (e.g., **estrogen receptor**) or growth factor receptors (e.g., **HER2**), not IgE. *Rheumatoid arthritis* - **Omalizumab** is not used for **rheumatoid arthritis (RA)**; RA is an autoimmune disease primarily involving **T-cells and cytokines** like **TNF-alpha** and **IL-6**. - Treatment for RA typically includes **DMARDs** (disease-modifying antirheumatic drugs) and **biological agents** that target specific inflammatory pathways (e.g., **adalimumab**, **etanercept**). *Chronic obstructive pulmonary disease (COPD)* - **Omalizumab** is not indicated for **COPD**, which is primarily characterized by chronic inflammation of the airways and **emphysema**, largely caused by smoking. - COPD management focuses on bronchodilators, corticosteroids, and oxygen therapy, with no role for IgE-targeting therapy.

Q: Which of the following is a selective serotonin and norepinephrine reuptake inhibitor?

Venlafaxine. ***Venlafaxine*** - **Venlafaxine** is a commonly used antidepressant that inhibits the reuptake of both **serotonin** and **norepinephrine**, making it an SNRI. - Its dual mechanism of action can be effective for a broad range of depressive and anxiety disorders. *Fluoxetine* - **Fluoxetine** is a **selective serotonin reuptake inhibitor (SSRI)**, primarily affecting serotonin levels in the brain. - It does not significantly inhibit norepinephrine reuptake and, thus, is not classified as an SNRI. *Sertraline* - **Sertraline** is another widely prescribed antidepressant that is also a **selective serotonin reuptake inhibitor (SSRI)**. - It works mainly by increasing serotonin availability in the synaptic cleft. *Aripiprazole* - **Aripiprazole** is an **atypical antipsychotic** medication, often used as an adjunct therapy for depression, but its primary mechanism is partial agonism at dopamine D2 and serotonin 5-HT1A receptors, and antagonism at serotonin 5-HT2A receptors. - It is not classified as a selective serotonin and norepinephrine reuptake inhibitor.

Q: Which steroid has the maximum mineralocorticoid activity?

Fludrocortisone. ***Fludrocortisone*** - **Fludrocortisone** is a synthetic corticosteroid specifically designed to have potent **mineralocorticoid activity**, with significant sodium-retaining properties. - Its high affinity for **mineralocorticoid receptors** distinguishes it from other steroids and makes it effective in treating conditions like **Addison's disease** and **postural orthostatic tachycardia syndrome (POTS)** due to its ability to retain sodium and water. *DOCA (Deoxycorticosterone acetate)* - While **DOCA** does possess significant **mineralocorticoid activity** and was historically used for this purpose, **fludrocortisone** is generally considered to have a stronger and more sustained effect in clinical practice. - **DOCA's** mineralocorticoid potency is substantial but slightly less than that of **fludrocortisone** when compared on a weight basis for equivalent sodium retention. *Prednisolone* - **Prednisolone** is primarily a **glucocorticoid** with potent anti-inflammatory and immunosuppressive effects. - It has minimal to negligible **mineralocorticoid activity** and is not used for salt retention purposes. *Triamcinolone* - **Triamcinolone** is a potent **glucocorticoid** with a long duration of action and is known for its strong anti-inflammatory properties. - It has virtually no **mineralocorticoid activity**, making it unsuitable for conditions requiring sodium retention.

Q: Which statin is considered most potent based on mg-to-mg LDL reduction capability?

Rosuvastatin. ***Rosuvastatin*** - **Rosuvastatin** is known for its high potency, achieving significant **LDL-C reduction** at relatively low doses. - It is often considered the most potent statin on a **milligram-to-milligram basis**. *Simvastatin* - **Simvastatin** is a moderate-intensity statin, not as potent as rosuvastatin or atorvastatin in reducing LDL-C. - While effective, it typically requires higher doses to achieve comparable **LDL-C reductions** seen with high-potency statins. *Pravastatin* - **Pravastatin** is a hydrophilic statin, generally considered to be of lower potency compared to other statins like rosuvastatin and atorvastatin. - It is often used in patients with **hepatic dysfunction** due to its different metabolic profile but offers less aggressive **LDL-C reduction**. *Atorvastatin* - **Atorvastatin** is a high-intensity statin, very effective in reducing LDL-C, and often used for aggressive lipid lowering. - While highly potent, **atorvastatin** is generally considered slightly less potent than **rosuvastatin** on a mg-to-mg basis, though both are used for high-intensity lipid therapy.

Q: Which of the following antiepileptic drugs is most classically associated with causing hirsutism?

Phenytoin. ***Phenytoin*** - **Phenytoin** is the **most classically associated** antiepileptic drug with **hirsutism**, which is abnormal/excessive growth of hair [1]. - The mechanism involves changes in **androgen metabolism** and stimulation of hair follicle growth. - Other cosmetic side effects include **gingival hyperplasia** and **coarsening of facial features** [1].*Valproate* - Valproate can paradoxically cause both **hair loss (alopecia)** and **hirsutism**, particularly in women and children. - However, phenytoin has a **stronger and more classical association** with hirsutism. - Valproate is also known for **weight gain**, **hepatotoxicity**, **pancreatitis**, and **teratogenicity**.*Carbamazepine* - Carbamazepine's common side effects include **drowsiness**, **dizziness**, **diplopia**, and **hyponatremia**. - It is not classically linked to **hirsutism** as a prominent adverse effect. - Can cause **agranulocytosis** and **Stevens-Johnson syndrome** in rare cases.*Phenobarbitone* - Phenobarbitone is an older antiepileptic drug associated with **sedation**, **cognitive impairment**, and **dependence**. - It does not commonly cause **hirsutism**. - Also causes **enzyme induction** leading to multiple drug interactions.

Q: What is the iodine content percentage in amiodarone?

20 - 40%. ***20 - 40%*** - **Amiodarone** is highly lipophilic and contains a significant amount of **iodine**, typically comprising around **37.5%** of its molecular weight. - This high iodine content is responsible for many of its **adverse effects**, particularly those related to thyroid dysfunction. *10 - 20%* - This range is too low; the actual iodine content in **amiodarone** is considerably higher, making it a prominent feature of the drug's chemical structure. - A lower iodine percentage would likely result in fewer **thyroid-related side effects**. *40 - 60%* - While amiodarone has a high iodine content, 40-60% is slightly above the generally accepted range. - Iodine constitutes a substantial but not an overwhelming majority of the drug's molecular mass. *60 - 80%* - This range is significantly higher than the actual iodine content in **amiodarone**. - Such a high percentage would imply an even greater propensity for **iodine-induced adverse effects**.

Q: Which of the following drugs acts directly to induce an erection without the need for sexual stimulation?

Alprostadil. ***Alprostadil***- **Alprostadil** is a **prostaglandin E1** analog that can directly induce vasodilation in the penile arteries, leading to an erection without sexual stimulation [1].- It is typically administered via **intracavernosal injection** or as a **urethral suppository**.*Sildenafil*- **Sildenafil** is a **PDE5 inhibitor** that works by enhancing the effects of **nitric oxide**, which is released in response to sexual stimulation [2, 3].- It requires **sexual arousal** to be effective, as it doesn't directly initiate the erectile process [2, 3].*Tadalafil*- Similar to sildenafil, **tadalafil** is also a **PDE5 inhibitor** that works by increasing cGMP levels and promoting smooth muscle relaxation [2, 3].- Its action is dependent on the release of **nitric oxide** triggered by sexual stimulation [2, 3].*Testosterone*- **Testosterone** is a hormone involved in sex drive and overall erectile function over time, but it does not directly or acutely induce an erection.- Its primary role in erectile dysfunction is in cases of **hypogonadism**, and it requires sexual stimulation for its effects on erection.

Q: Which of the following statements about Conivaptan is correct?

It is a vasopressin antagonist.. ***It is a vasopressin antagonist.*** * **Conivaptan** is a non-peptide, dual **vasopressin V1A and V2 receptor antagonist**, meaning it blocks the action of vasopressin. * By blocking vasopressin, it promotes **aquaresis** (excretion of solute-free water), which is beneficial in conditions like **hyponatremia**. * *It selectively acts on V2 receptors.* * **Conivaptan** is a **dual antagonist**, blocking both **V1A and V2 receptors**, not just V2. * **Tolvaptan**, in contrast, is a selective **V2 receptor antagonist**. * *It is administered orally.* * **Conivaptan** is typically administered intravenously, particularly in hospital settings for acute hyponatremia. * **Tolvaptan** is the orally administered vasopressin antagonist. * *All of the options.* * Since Conivaptan is not selectively acting on V2 receptors and is not administered orally, this option is incorrect.

Q: Which of the following potassium-sparing diuretics was the first to be shown to reduce cardiac mortality in chronic heart failure patients?

Spironolactone. ***Spironolactone*** - **Spironolactone** was the first potassium-sparing diuretic shown to reduce **cardiac mortality** in patients with **chronic heart failure** in the **RALES trial** (Randomized Aldactone Evaluation Study). - Its beneficial effects in heart failure are primarily attributed to its **aldosterone receptor antagonist** properties, which counteract the harmful effects of aldosterone on the myocardium and vasculature, rather than just its diuretic effect. *Amiloride* - **Amiloride** is a potassium-sparing diuretic that works by directly inhibiting **epithelial sodium channels (ENaC)** in the collecting duct. - While it helps in potassium conservation, it has not been shown to significantly reduce cardiac mortality in chronic heart failure patients in clinical trials. *Triamterene* - **Triamterene** is another potassium-sparing diuretic that also directly inhibits **ENaC** in the collecting duct, similar to amiloride. - Like amiloride, it is used to prevent hypokalemia but lacks evidence for significant **cardiac mortality reduction** in chronic heart failure. *Eplerenone* - **Eplerenone** is a selective **aldosterone receptor antagonist**, similar to spironolactone, with fewer hormonal side effects. - While it has been shown to reduce **cardiac mortality** in chronic heart failure (e.g., in the EMPHASIS-HF trial), it was introduced later than spironolactone and was not the *first* to demonstrate this benefit.

Question 1

Which of the following is NOT a mechanism of action of theophylline in bronchial asthma?

Accepted Answer

Beta-2 receptor stimulation

Answer

Adenosine receptor antagonism

Answer

Increased histone deacetylation

Answer

Phosphodiesterase inhibition

Question 2

Omalizumab is primarily used in the treatment of which condition?

Accepted Answer

Asthma

Answer

Breast carcinoma

Answer

Rheumatoid arthritis

Answer

Chronic obstructive pulmonary disease (COPD)

Question 3

Which of the following is a selective serotonin and norepinephrine reuptake inhibitor?

Accepted Answer

Venlafaxine

Answer

Fluoxetine

Answer

Sertraline

Answer

Aripiprazole

Question 4

Which steroid has the maximum mineralocorticoid activity?

Accepted Answer

Fludrocortisone

Answer

DOCA

Answer

Prednisolone

Answer

Triamcinolone

Question 5

Which statin is considered most potent based on mg-to-mg LDL reduction capability?

Accepted Answer

Rosuvastatin

Answer

Simvastatin

Answer

Pravastatin

Answer

Atorvastatin

Question 6

Which of the following antiepileptic drugs is most classically associated with causing hirsutism?

Accepted Answer

Phenytoin

Answer

Valproate

Answer

Carbamazepine

Answer

Phenobarbitone

Question 7

What is the iodine content percentage in amiodarone?

Accepted Answer

20 - 40%

Answer

10 - 20%

Answer

40 - 60%

Answer

60 - 80%

Question 8

Which of the following drugs acts directly to induce an erection without the need for sexual stimulation?

Accepted Answer

Alprostadil

Answer

Sildenafil

Answer

Tadalafil

Answer

Testosterone

Question 9

Which of the following statements about Conivaptan is correct?

Accepted Answer

It is a vasopressin antagonist.

Answer

It selectively acts on V2 receptors.

Answer

It is administered orally.

Answer

All of the options.

Question 10

Which of the following potassium-sparing diuretics was the first to be shown to reduce cardiac mortality in chronic heart failure patients?

Accepted Answer

Spironolactone

Answer

Amiloride

Answer

Triamterene

Answer

Eplerenone

NEET-PG 2012 — Pharmacology