NEET-PG 2020 - Pharmacology PYQs Practice Questions

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. [Practice more Pharmacology PYQs on OnCourse]

Q: Patient with pulmonary fibrosis. Which antiarrhythmic drug is contraindicated?

Amiodarone. Amiodarone - **Amiodarone** is contraindicated in patients with pulmonary fibrosis due to its well-known and potentially severe pulmonary toxicity, which can exacerbate existing lung conditions or induce new ones like **interstitial lung disease**. Dose-related pulmonary toxicity is the most important adverse effect, and potentially fatal pulmonary fibrosis can be observed even at low doses [1]. - Its long half-life means that its toxic effects, including **pulmonary toxicity**, can persist for an extended period even after discontinuation [1], [2]. *Flecainide* - **Flecainide** is a Class IC antiarrhythmic drug primarily associated with cardiac side effects and is generally not contraindicated in patients with pulmonary fibrosis. - Its main risks include **proarrhythmia**, especially in patients with structural heart disease, but not pulmonary issues [3]. *IV ibutilide* - **IV ibutilide** is a Class III antiarrhythmic agent used for rapid conversion of atrial fibrillation/flutter and is not specifically contraindicated in pulmonary fibrosis. - Its primary concern is the risk of **QT prolongation** and **Torsades de Pointes**, rather than pulmonary complications. *Lidocaine* - **Lidocaine** is a Class IB antiarrhythmic typically used for ventricular arrhythmias, especially in the setting of acute myocardial infarction. It is not contraindicated in pulmonary fibrosis. - Its main side effects are **neurological (e.g., seizures, paresthesias)** at higher doses, not pulmonary complications. [Practice more Pharmacology PYQs on OnCourse]

Q: A patient on lithium therapy developed hypertension and was started on a thiazide diuretic. After a few days, he developed coarse tremors and other symptoms suggestive of lithium toxicity. What is the probable mechanism of interaction between thiazide diuretics and lithium?

Thiazide increases the tubular reabsorption of lithium. ***Thiazide increases the tubular reabsorption of lithium*** - Thiazide diuretics cause a decrease in sodium reabsorption in the distal convoluted tubule, leading to increased sodium excretion in urine. - The kidneys, in an attempt to conserve sodium, increase reabsorption in the proximal tubule. Because **lithium** is reabsorbed similarly to sodium in the proximal tubule, this increased reabsorption also affects lithium, leading to a rise in its plasma concentration and toxicity. *Thiazide inhibits the metabolism of lithium* - Lithium is primarily excreted by the kidneys and is not significantly metabolized in the body. - Thiazide diuretics do not affect enzyme systems responsible for drug metabolism. *Thiazides act as an add on the drug to lithium* - This statement is vague and does not explain a mechanism of interaction leading to toxicity. - While both drugs might be prescribed concurrently for different conditions, "add on" does not describe a pharmacological interaction causing altered drug levels. *None of the above* - This option is incorrect because a clear and well-understood mechanism for the interaction between thiazide diuretics and lithium exists. [Practice more Pharmacology PYQs on OnCourse]

Q: Which of the following is not considered a prokinetic agent?

Diphenylmethane. Diphenylmethane derivatives (e.g., bisacodyl, sodium picosulfate) are stimulant laxatives, not prokinetic agents. While they do increase colonic motility, they work by direct stimulation of the colonic mucosa and myenteric plexus, causing increased water secretion and peristalsis [3]. Prokinetic agents specifically enhance coordinated gastrointestinal motility through modulation of neurotransmitters (acetylcholine, dopamine, serotonin, motilin), whereas laxatives work through different mechanisms (osmotic effects, stimulation, bulk formation). Therefore, diphenylmethane derivatives are classified as laxatives, not prokinetics. Dopamine antagonist - Dopamine antagonists like metoclopramide and domperidone block D2 receptors in the chemoreceptor trigger zone and GI tract, enhancing acetylcholine release and promoting gastric emptying [2]. - They are commonly used as prokinetic agents and antiemetics [2]. 5HT4 agonist - 5HT4 agonists (e.g., cisapride, prucalopride) stimulate serotonin receptors in the enteric nervous system, increasing acetylcholine release and enhancing colonic motility [1]. - They are effective prokinetic agents for conditions like chronic constipation and gastroparesis [1]. Macrolides - Certain macrolide antibiotics, such as erythromycin, act as motilin receptor agonists at sub-antibiotic doses. - By mimicking motilin, they stimulate gastric and intestinal contractions (phase III of migrating motor complex), functioning as prokinetic agents. [Practice more Pharmacology PYQs on OnCourse]

Q: Misoprostol used in the induction of labour is an analogue of which of the following type of prostaglandin?

PG E1. ***PG E1*** - **Misoprostol** is a synthetic analogue of **prostaglandin E1 (PGE1)**, which is used for cervical ripening and uterine contractions in labor induction. - PGE1 analogues help to soften the cervix, increase its compliance, and stimulate uterine smooth muscle contraction. *PG E2* - **Dinoprostone** is a synthetic analogue of **prostaglandin E2 (PGE2)**, commonly used for cervical ripening and induction of labor. - While PGE2 also induces labor, misoprostol specifically mimics the actions of PGE1. *PG I2* - **Prostacyclin (PGI2)** is primarily known for its role in inhibiting platelet aggregation and causing vasodilation. - It is not routinely used for labor induction due to its primary vascular effects and lack of direct uterine contractile properties at relevant doses. *PG F2alpha* - **Prostaglandin F2-alpha (PGF2α)**, such as **carboprost**, is used for postpartum hemorrhage to cause strong uterine contractions. - While it causes uterine contractions, its primary obstetric use is not for labor induction but rather for stimulating aggressive uterine contraction to stop bleeding. [Practice more Pharmacology PYQs on OnCourse]

Question 1

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 2

Patient with pulmonary fibrosis. Which antiarrhythmic drug is contraindicated?

Accepted Answer

Amiodarone

Answer

Flecainide

Answer

Lidocaine

Answer

IV ibutilide

Question 3

A patient on lithium therapy developed hypertension and was started on a thiazide diuretic. After a few days, he developed coarse tremors and other symptoms suggestive of lithium toxicity. What is the probable mechanism of interaction between thiazide diuretics and lithium?

Accepted Answer

Thiazide increases the tubular reabsorption of lithium

Answer

Thiazide inhibits the metabolism of lithium

Answer

Thiazides act as an add-on drug to lithium

Answer

None of the above

Question 4

Which of the following is not considered a prokinetic agent?

Accepted Answer

Diphenylmethane

Answer

Dopamine antagonist

Answer

5HT4 agonist

Answer

Macrolides

Question 5

Misoprostol used in the induction of labour is an analogue of which of the following type of prostaglandin?

Accepted Answer

PG E1

Answer

PG E2

Answer

PG I2

Answer

PG F2alpha

Question 6

A patient diagnosed with Rheumatoid arthritis was on medications. After 2 years, he developed a blurring vision and was found to have corneal opacity. Which drug is most likely to cause this?

Accepted Answer

Chloroquine

Answer

Sulfasalazine

Answer

Leflunomide

Answer

Methotrexate

Question 7

A person was given a muscle relaxant that competitively blocks nicotinic receptors. Which of the following drugs is used for reversal of muscle relaxation after surgery?

Accepted Answer

Neostigmine

Answer

Carbachol

Answer

Succinylcholine

Answer

Physostigmine

Question 8

What is the Drug of Choice (DOC) for Onychomycosis?

Accepted Answer

Terbinafine

Answer

Fluconazole

Answer

Itraconazole

Answer

Nystatin

Question 9

Which of the following drugs can be given in patients of primary pulmonary hypertension?

Accepted Answer

Bosentan

Answer

Icatibant

Answer

Sodium nitroprusside

Answer

Labetalol

Question 10

Which of the following vitamins, when taken at higher doses, can cause cystoid macular edema?

Accepted Answer

Niacin

Answer

Vitamin A

Answer

Vitamin D

Answer

Vitamin E

NEET-PG 2020 — Pharmacology