NEET-PG 2024 - Pharmacology Practice Questions

Q: Which of the following is represented in the below figure by drug X?

Epsilon Amino Caproic acid. ***Epsilon Amino Caproic acid*** - The diagram shows **Drug X** inhibiting the activation of plasminogen to plasmin, thereby reducing fibrinolysis. - **Epsilon aminocaproic acid (EACA)** is an antifibrinolytic drug that competitively inhibits plasminogen activators, thus preventing the formation of plasmin. *Clopidogrel* - **Clopidogrel** is an **antiplatelet drug** that works by inhibiting the P2Y12 ADP receptor on platelets, preventing platelet aggregation. - Its mechanism of action is distinct from the fibrinolytic pathway shown in the diagram. *Tenecteplase* - **Tenecteplase** is a **thrombolytic drug** (fibrinolytic) that *activates* plasminogen to plasmin. - This action is opposite to what Drug X depicts, which *inhibits* the fibrinolytic pathway. *Streptokinase* - **Streptokinase** is a **thrombolytic drug** that activates plasminogen to plasmin, promoting fibrinolysis. - Like tenecteplase, its action is opposite to Drug X, which inhibits the fibrinolytic pathway. *Aspirin* - **Aspirin** is an **antiplatelet drug** that inhibits cyclooxygenase-1 (COX-1), thereby reducing thromboxane A2 production and platelet aggregation. - It does not directly interact with the plasminogen-plasmin system as depicted for Drug X.

Q: A patient presents with hypertension and has a history of renal stones, along with several episodes of renal colic. Which diuretic is the most appropriate to use?

Hydrochlorothiazide. **Hydrochlorothiazide** - **Thiazide diuretics** like hydrochlorothiazide reduce urinary calcium excretion, which is beneficial in patients with a history of **calcium renal stones**. - This effect helps prevent the recurrence of renal stones while also treating hypertension. - Among thiazide and thiazide-like diuretics, hydrochlorothiazide has the **most established evidence** for preventing calcium stone recurrence. *Furosemide* - Furosemide is a **loop diuretic** that increases urinary calcium excretion, which would exacerbate the risk of renal stone formation. - While effective for hypertension, its effect on calcium makes it unsuitable for this patient. *Ethacrynic acid* - Ethacrynic acid is also a **loop diuretic** with similar effects to furosemide, including increasing urinary calcium excretion. - This makes it an inappropriate choice for a patient with a history of renal stones. *Spironolactone* - Spironolactone is a **potassium-sparing diuretic** that works by antagonizing aldosterone, primarily affecting sodium and potassium excretion. - It does not significantly impact urinary calcium excretion in a way that would prevent calcium renal stones, nor is it a first-line agent for hypertension with co-existing renal stones. *Indapamide* - Indapamide is a **thiazide-like diuretic** with some calcium-retaining properties, but it is less effective than hydrochlorothiazide in reducing calcium excretion. - While it can be used for hypertension, **hydrochlorothiazide is preferred** specifically for preventing calcium stone recurrence due to stronger evidence and greater effect on reducing urinary calcium.

Q: Which of the following is the most appropriate treatment for an overactive bladder in a patient with dementia?

Tolterodine. ***Tolterodine*** - **Tolterodine** is a **muscarinic antagonist** that blocks acetylcholine receptors in the bladder, reducing detrusor muscle contractions and overactive bladder symptoms. - Unlike some other anticholinergics like oxybutynin, it has a **lower propensity to cross the blood-brain barrier** and thus a reduced risk of exacerbating cognitive impairment in patients with dementia. *Mirabegron* - **Mirabegron** is a **beta-3 adrenergic agonist** that relaxes the detrusor muscle, increasing bladder capacity. - While it has a different mechanism of action and is less likely to cause anticholinergic cognitive side effects than older anticholinergics, it can still cause **hypertension** and **tachycardia**, which may be problematic in elderly patients with comorbidities. *Behavioral therapy/bladder training* - **Behavioral therapy** and **bladder training** are important first-line treatments for overactive bladder. - However, for patients with **dementia**, cognitive impairment often makes adherence to and understanding of these complex therapies challenging or impossible without significant caregiver support. *Oxybutynin* - **Oxybutynin** is an **anticholinergic drug** that is effective for overactive bladder. - However, it has a **high affinity for muscarinic receptors** in the brain and readily crosses the blood-brain barrier, significantly increasing the risk of **cognitive impairment, confusion, and delirium** in elderly patients, especially those with pre-existing dementia. *Trospium* - **Trospium** is a **quaternary amine anticholinergic** that is hydrophilic and has minimal blood-brain barrier penetration. - While theoretically safer than oxybutynin in terms of CNS effects, it has **lower bladder selectivity** compared to tolterodine and may cause more peripheral anticholinergic side effects (dry mouth, constipation).

Q: Which of the following statements regarding the patch shown in the figure is correct?

Excessive use can result in methemoglobinemia.. ***Excessive use can result in methemoglobinemia.*** - The patch shown is likely an **EMLA patch**, which contains **lidocaine** and **prilocaine**. Excessive absorption of prilocaine, especially with large doses or prolonged application, can lead to the formation of **methemoglobinemia**. - **Prilocaine** is metabolized into **ortho-toluidine**, which is an oxidizing agent that can convert hemoglobin to methemoglobin, reducing the blood's oxygen-carrying capacity. *It is an equal mixture of local anesthetics.* - The EMLA patch is a 1:1 mixture of **lidocaine** and **prilocaine**, but the claim that it contains "an equal mixture of local anesthetics" is vague and could imply other compositions not specific to EMLA. - While it's an equal ratio of two specific local anesthetics, the option's wording is not precise enough to be the *most correct* statement. *5 ml of a 5 percent mixture contains 50 mg of lignocaine.* - A 5% solution means 5 grams (5000 mg) per 100 ml. Therefore, 1 ml contains 50 mg of lignocaine. - Thus, 5 ml of a 5% mixture would contain 250 mg of **lignocaine**, not 50 mg. This statement is mathematically incorrect. *It contains lignocaine and ropivacaine in a ratio of 50 percent each.* - **EMLA patches** contain **lidocaine** (lignocaine) and **prilocaine**, not ropivacaine. - While it is a 50% concentration for each active ingredient, the specific combination of local anesthetics mentioned in this option is incorrect. *It should be applied for at least 2 hours before minor procedures.* - For most minor procedures, **EMLA cream** typically requires **30-60 minutes** of application time to achieve adequate topical anesthesia. - While longer application times (up to 2 hours) may enhance depth of anesthesia for certain procedures, stating that it "should be applied for at least 2 hours" is excessive and not a standard recommendation for minor procedures.

Q: Lidocaine is used in a loading dose for the treatment of arrhythmias. The loading dose of this drug depends upon which of the following factors?

Volume of distribution. ***Volume of distribution*** - The **loading dose** of a drug is primarily determined by its **volume of distribution (Vd)** and the **target plasma concentration**. - A larger **Vd** means the drug distributes widely into tissues, requiring a larger loading dose to achieve the desired concentration in the central compartment. *Clearance* - **Clearance** dictates the **maintenance dose** needed to sustain a steady-state concentration once the loading dose has been administered. - It reflects the rate at which the drug is eliminated from the body, not how much is initially needed to fill the distribution volume. *Half-life* - **Half-life** determines the **time required to reach steady-state** and the **dosing interval** for maintaining therapeutic concentrations. - While related to clearance and Vd, it does not directly determine the magnitude of the initial loading dose itself. *Bioavailability* - **Bioavailability** is the fraction of administered drug that reaches the systemic circulation in an unchanged form. - It influences the oral dose required to achieve a certain plasma concentration, but the concept of loading dose is typically considered for the intravenous route where bioavailability is 100%. *Elimination rate constant* - The **elimination rate constant (ke)** describes the rate of drug elimination and is related to clearance and volume of distribution (ke = Cl/Vd). - Like clearance, it determines the **maintenance dose** and dosing frequency, not the initial loading dose required to achieve therapeutic levels.

Q: A person was taking an antihypertensive drug and continued taking it despite developing constipation, dry mouth, and dizziness. He was taking it regularly but forgot to take it during a trip abroad and has now developed a hypertensive emergency. Which antihypertensive was he likely taking?

Clonidine. **Clonidine** - The described symptoms of **constipation, dry mouth, and dizziness** are common side effects of **clonidine**, an alpha-2 adrenergic agonist. - The development of a **hypertensive emergency** upon abrupt cessation of the drug strongly suggests clonidine, as it is known for causing **rebound hypertension** due to a sudden increase in sympathetic outflow. *Amlodipine* - **Amlodipine**, a dihydropyridine calcium channel blocker, primarily causes **peripheral edema, headache, and flushing**, not typically constipation or rebound hypertension upon withdrawal. - While it can cause dizziness, the combination of side effects and withdrawal symptoms does not fit amlodipine. *Lisinopril* - **Lisinopril**, an ACE inhibitor, is known for causing **cough and angioedema**. - It does not typically cause constipation, dry mouth, or rebound hypertension upon discontinuation. *Telmisartan* - **Telmisartan**, an angiotensin receptor blocker (ARB), generally has a **favorable side effect profile** and does not commonly cause constipation or dry mouth. - Withdrawal of ARBs does not typically lead to a **hypertensive emergency** in the way clonidine does. *Metoprolol* - **Metoprolol**, a beta-blocker, can cause **fatigue and bradycardia** but does not typically cause the anticholinergic effects (dry mouth, constipation) seen with clonidine. - While abrupt withdrawal of beta-blockers can lead to rebound tachycardia and hypertension, the severity and acute nature of the hypertensive emergency described is more characteristic of clonidine withdrawal.

Q: A patient being treated for hypertriglyceridemia developed flushing, gout, hyperglycemia, and raised liver enzymes. Which drug is the most likely cause?

Nicotinic acid. ***Nicotinic acid*** - **Nicotinic acid (Niacin)** is known to cause **flushing** due to prostaglandin release. - It also commonly leads to **hyperglycemia**, **hyperuricemia** (which can precipitate gout), and **elevated liver enzymes** as side effects. *Atorvastatin* - While atorvastatin can cause **elevated liver enzymes** and, less commonly, **myopathy**, it does not typically cause flushing, gout, or hyperglycemia. - Its primary role is to lower **LDL cholesterol**, with a lesser effect on triglycerides. *Fenofibrate* - **Fenofibrate** is used to treat hypertriglyceridemia and can rarely cause **elevated liver enzymes** and **gallstones**. - It is not associated with significant flushing, hyperglycemia, or gout. *Gemfibrozil* - **Gemfibrozil** is another fibrate used for hypertriglyceridemia treatment. - While it can cause **elevated liver enzymes** and **myopathy** (especially when combined with statins), it does not cause the characteristic flushing or hyperglycemia seen with nicotinic acid. *Ezetimibe* - **Ezetimibe** primarily inhibits cholesterol absorption and is generally well-tolerated. - Common side effects are mild and include abdominal pain and diarrhea, with no association to flushing, gout, or hyperglycemia.

Q: Which of the following drugs, when given with erythromycin, can cause QT prolongation and Torsades de Pointes?

Astemizole. ***Astemizole*** - **Astemizole** is a second-generation antihistamine that undergoes extensive metabolism by the **CYP3A4 enzyme**. - Concomitant use with **erythromycin**, a potent **CYP3A4 inhibitor**, significantly increases astemizole plasma concentrations, leading to **QT prolongation** and an elevated risk of **Torsades de Pointes**. *Cetirizine* - **Cetirizine** is another second-generation antihistamine that is primarily eliminated via **renal excretion** and does not undergo significant CYP450 metabolism. - Therefore, its co-administration with **erythromycin** does not typically lead to clinically significant drug interactions impacting cardiac repolarization. *Fexofenadine* - **Fexofenadine** is a second-generation antihistamine and active metabolite of terfenadine that is primarily eliminated via **biliary excretion** and has minimal hepatic metabolism. - While it is a substrate of **P-glycoprotein** (which can be inhibited by erythromycin), fexofenadine has a much safer cardiac profile and does not typically cause **QT prolongation** even with CYP3A4 inhibitors. *Loratadine* - **Loratadine** is a second-generation antihistamine that is metabolized by **CYP2D6** and **CYP3A4**, but its active metabolite, desloratadine, has a lower propensity for QT prolongation. - While erythromycin is a CYP3A4 inhibitor, the risk of **QT prolongation** with **loratadine** is generally considered much lower than with astemizole, even with concurrent use. *Promethazine* - **Promethazine** is a first-generation antihistamine and phenothiazine derivative that primarily acts as a **dopamine D2 receptor antagonist**. - While it can cause **QT prolongation** on its own at high doses, its metabolism is complex and not predominantly dependent on **CYP3A4** to the extent that interaction with **erythromycin** poses the same severe risk as with astemizole.

Q: A 45-year-old male with a history of chronic alcohol use is admitted to the hospital. He presents with anxiety, tremors, and agitation after his last drink 24 hours ago. Which of the following medications is most appropriate for controlling alcohol withdrawal symptoms?

Lorazepam. ***Lorazepam*** - **Lorazepam**, a **benzodiazepine**, is the first-line treatment for alcohol withdrawal symptoms due to its ability to enhance **GABAergic activity**, which is deficient during withdrawal. - Its **intermediate half-life** and **lack of active metabolites** make it suitable for patients with liver impairment, common in chronic alcohol users. *Fomepizole* - **Fomepizole** is an antidote used to treat poisoning from **methanol** or **ethylene glycol**, not alcohol withdrawal. - It works by inhibiting **alcohol dehydrogenase**, an enzyme involved in the metabolism of these toxic alcohols. *Disulfiram* - **Disulfiram** is an **aldehyde dehydrogenase inhibitor** used to deter alcohol consumption in recovering alcoholics by causing unpleasant reactions if alcohol is consumed. - It is **not used to treat acute alcohol withdrawal symptoms** and can be dangerous if given during withdrawal due to potential interactions. *Buspirone* - **Buspirone** is an **anxiolytic** that acts as a **serotonin receptor agonist** and is used for generalized anxiety disorder. - It is **ineffective for acute alcohol withdrawal** due to its slow onset of action and lack of anticonvulsant properties. *Naltrexone* - **Naltrexone** is an **opioid receptor antagonist** used for relapse prevention and reducing alcohol craving in patients with alcohol use disorder. - It is **not effective for acute alcohol withdrawal symptoms** and does not prevent seizures or delirium tremens, which are life-threatening complications of withdrawal.

Question 1

Which of the following is represented in the below figure by drug X?

Accepted Answer

Epsilon Amino Caproic acid

Answer

Clopidogrel

Answer

Tenecteplase

Answer

Aspirin

Answer

Streptokinase

Question 2

A patient presents with hypertension and has a history of renal stones, along with several episodes of renal colic. Which diuretic is the most appropriate to use?

Accepted Answer

Hydrochlorothiazide

Answer

Furosemide

Answer

Ethacrynic acid

Answer

Spironolactone

Answer

Indapamide

Question 3

Which of the following is the most appropriate treatment for an overactive bladder in a patient with dementia?

Accepted Answer

Tolterodine

Answer

Mirabegron

Answer

Behavioral therapy/bladder training

Answer

Oxybutynin

Answer

Trospium

Question 4

Which of the following statements regarding the patch shown in the figure is correct?

Accepted Answer

Excessive use can result in methemoglobinemia.

Answer

It is an equal mixture of local anesthetics.

Answer

5 ml of a 5 percent mixture contains 50 mg of lignocaine.

Answer

It contains lignocaine and ropivacaine in a ratio of 50 percent each.

Answer

It should be applied for at least 2 hours before minor procedures.

Question 5

Lidocaine is used in a loading dose for the treatment of arrhythmias. The loading dose of this drug depends upon which of the following factors?

Accepted Answer

Volume of distribution

Answer

Clearance

Answer

Half-life

Answer

Bioavailability

Answer

Elimination rate constant

Question 6

A person was taking an antihypertensive drug and continued taking it despite developing constipation, dry mouth, and dizziness. He was taking it regularly but forgot to take it during a trip abroad and has now developed a hypertensive emergency. Which antihypertensive was he likely taking?

Accepted Answer

Clonidine

Answer

Amlodipine

Answer

Lisinopril

Answer

Telmisartan

Answer

Metoprolol

Question 7

A patient being treated for hypertriglyceridemia developed flushing, gout, hyperglycemia, and raised liver enzymes. Which drug is the most likely cause?

Accepted Answer

Nicotinic acid

Answer

Atorvastatin

Answer

Fenofibrate

Answer

Ezetimibe

Answer

Gemfibrozil

Question 8

Which of the following drugs, when given with erythromycin, can cause QT prolongation and Torsades de Pointes?

Accepted Answer

Astemizole

Answer

Cetirizine

Answer

Loratadine

Answer

Promethazine

Answer

Fexofenadine

Question 9

A 45-year-old male with a history of chronic alcohol use is admitted to the hospital. He presents with anxiety, tremors, and agitation after his last drink 24 hours ago. Which of the following medications is most appropriate for controlling alcohol withdrawal symptoms?

Accepted Answer

Lorazepam

Answer

Fomepizole

Answer

Disulfiram

Answer

Buspirone

Answer

Naltrexone

Question 10

Which of the following statements about Ciclesonide is incorrect?

Accepted Answer

Oral candidiasis is common with its use.

Answer

It is a prodrug activated by bronchial esterase.

Answer

It has comparable efficacy to other inhalational corticosteroids.

Answer

It has fewer side effects than other inhalational corticosteroids.

Answer

It has low systemic bioavailability due to extensive first-pass metabolism.

NEET-PG 2024 — Pharmacology