NEET-PG 2013 - Pharmacology Practice Questions

Q: Which of the following is a benzylisoquinoline muscle relaxant?

Doxacurium. ***Doxacurium*** - **Doxacurium** is a long-acting, non-depolarizing neuromuscular blocker classified as a **benzylisoquinoline** compound [1]. - These agents are known for their minimal cardiovascular effects and lack of histamine release in therapeutic doses [1]. *Vecuronium* - **Vecuronium** is an **aminosteroid** non-depolarizing neuromuscular blocker [2]. - It is known for its intermediate duration of action and minimal cardiovascular effects [1]. *Rocuronium* - **Rocuronium** is also an **aminosteroid** non-depolarizing neuromuscular blocker [2]. - It has a rapid onset of action, making it suitable for rapid sequence intubation, and can be reversed by **sugammadex**. *Pancuronium* - **Pancuronium** is an **aminosteroid** non-depolarizing neuromuscular blocker with a long duration of action [1]. - It is associated with a vagolytic effect that can cause an increase in **heart rate** and **blood pressure** [1].

Q: Which medication increases insulin secretion from beta cells?

Repaglinide. ***Repaglinide*** - This medication is a **meglitinide analog** that stimulates **insulin release** from pancreatic beta cells by closing ATP-sensitive potassium channels. - Its fast onset and short duration of action make it particularly useful for controlling **postprandial glucose** excursions. *Metformin* - This medication primarily works by **decreasing hepatic glucose production** and improving insulin sensitivity in peripheral tissues. - It does **not directly stimulate insulin secretion** from beta cells; thus, it carries a lower risk of hypoglycemia compared to sulfonylureas or meglitinides. *Pramlintide* - This is an **amylin analog** that works by slowing gastric emptying, suppressing postprandial glucagon secretion, and increasing satiety. - It is an **injectable medication** used as an adjunct to insulin therapy and does not directly enhance insulin secretion from beta cells. *Pioglitazone* - This drug is a **thiazolidinedione** that improves insulin sensitivity in target tissues (e.g., muscle, fat, liver) by activating **peroxisome proliferator-activated receptor-gamma (PPAR-γ)**. - While it improves the body's response to insulin, it does **not directly stimulate insulin secretion** from the beta cells.

Q: Which of the following antidiabetic drugs (other than insulin) is indicated as adjunct therapy for the management of both type I and type II diabetes mellitus?

Pramlintide. Pramlintide - Pramlintide is an amylin analog indicated as an adjunct therapy to insulin for both type 1 and type 2 diabetes, helping to regulate post-prandial glucose. - It slows gastric emptying, suppresses postprandial glucagon secretion, and promotes satiety, leading to reduced insulin requirements and improved glycemic control. Sulphonylureas - Sulphonylureas primarily stimulate insulin secretion from pancreatic beta cells, making them effective only in Type 2 diabetes where some beta-cell function is preserved [2]. - They are not indicated for Type 1 diabetes because these patients have absolute insulin deficiency due to beta cell destruction. Metformin - Metformin is a biguanide that primarily reduces hepatic glucose production and improves insulin sensitivity in peripheral tissues. - It is a first-line treatment for Type 2 diabetes but is generally not used for Type 1 diabetes as it does not address the fundamental lack of insulin. Acarbose - Acarbose is an alpha-glucosidase inhibitor that works by delaying carbohydrate absorption from the gastrointestinal tract, thus reducing postprandial glucose spikes [1]. - While it can be used in Type 2 diabetes to manage postprandial hyperglycemia, it is not typically indicated as an adjunct for Type 1 diabetes alongside insulin [3].

Q: Which of the following statements about sitagliptin is false?

Cannot be used orally. ***Cannot be used orally*** - This statement is **false** because **sitagliptin** is an **oral medication** approved for the treatment of type 2 diabetes mellitus. - As a **DPP-4 inhibitor**, it is designed to be taken by mouth to increase incretin hormone levels. *Used in type II diabetes mellitus* - This statement is **true** as **sitagliptin** is a commonly prescribed **oral antidiabetic drug** for the management of type 2 diabetes. - It works by inhibiting the enzyme **dipeptidyl peptidase-4 (DPP-4)**, which increases levels of **GLP-1** and **GIP** to enhance insulin secretion and reduce glucagon secretion. *Used in combination with other oral hypoglycemic agents* - This statement is **true** as **sitagliptin** is often used as **add-on therapy** with other oral hypoglycemic agents like **metformin** or a **sulfonylurea** when monotherapy is insufficient. - This combination approach helps achieve better glycemic control by targeting different mechanisms of action. *All of the above statements are true* - This statement is **false** because the first statement "Cannot be used orally" is incorrect. - Since sitagliptin is indeed an oral medication, not all the above statements are true, making this option incorrect.

Q: What is a potential risk associated with the use of thiazolidinediones in the treatment of type 2 diabetes?

Heart failure. ***Heart failure*** - Thiazolidinediones (TZDs), such as **pioglitazone** and **rosiglitazone**, can cause **fluid retention** and **volume expansion**, which may precipitate or worsen congestive heart failure. - This risk is higher in patients with pre-existing cardiac conditions and is a significant concern for these drugs. *Pulmonary fibrosis* - **Pulmonary fibrosis** is not a known or common adverse effect associated with thiazolidinedione use. - This condition is typically linked to certain other medications (e.g., **amiodarone**, **methotrexate**) or systemic diseases. *Myocarditis* - **Myocarditis**, inflammation of the heart muscle, is not a recognized side effect of thiazolidinediones. - Myocarditis is more commonly caused by viral infections, autoimmune diseases, or hypersensitivity reactions to certain drugs, but not TZDs. *Renal dysfunction* - While TZDs can cause fluid retention, they do not directly cause **renal dysfunction** or damage the kidneys. - In fact, some studies suggest they may have renoprotective effects due to reduced proteinuria, although fluid balance needs careful monitoring in patients with impaired renal function.

Q: What conditions is Metformin primarily used to treat?

Both Type 2 Diabetes and Polycystic Ovary Syndrome (PCOS). ***Both Type 2 Diabetes and Polycystic Ovary Syndrome (PCOS)*** - **Metformin** is a first-line treatment for **Type 2 Diabetes** due to its ability to decrease hepatic glucose production and improve insulin sensitivity [1], [2]. - It is also commonly used off-label for **PCOS** to improve insulin resistance, ovulation, and reduce androgen levels. *Only Type 2 Diabetes* - While Metformin is a cornerstone for **Type 2 Diabetes** treatment, stating "only" is incorrect as it has other significant therapeutic uses [2]. - Its benefits extend beyond diabetes management, particularly in conditions involving **insulin resistance**. *Only Polycystic Ovary Syndrome (PCOS)* - Metformin is used in **PCOS**, but it is not the sole condition it treats, and its primary indication remains **Type 2 Diabetes** [2]. - This option incorrectly limits its application to just one condition, overlooking its major role in diabetes. *Pregnancy Induced Hypertension* - **Metformin** is not indicated for the treatment of **pregnancy-induced hypertension** (gestational hypertension). - Treatment for pregnancy-induced hypertension typically involves medications like **labetalol**, **methyldopa**, or **nifedipine**, with delivery being the definitive management for severe cases.

Q: Which of the antithyroid drugs inhibits iodine trapping?

Thiocyanates. ***Thiocyanates*** - **Thiocyanates** are competitive inhibitors of the **sodium-iodide symporter (NIS)**, which is responsible for actively transporting iodide into thyroid follicular cells (iodine trapping) [1]. - By blocking NIS, thiocyanates prevent the thyroid gland from accumulating iodide, thereby inhibiting thyroid hormone synthesis [1]. *Radioactive iodine* - **Radioactive iodine (RAI)** primarily works by being taken up by thyroid cells and emitting **beta particles**, which destroy the thyroid tissue [3]. - It does not inhibit iodine trapping, but rather uses the trapping mechanism to concentrate in the thyroid and exert its destructive effect [3]. *Iodides* - **Iodides** (e.g., Lugol's solution) paradoxically inhibit organification and hormone release from the thyroid gland, an effect known as the **Wolff-Chaikoff effect** [2]. - They also decrease the vascularity and size of the thyroid gland, making them useful in preparing patients for thyroidectomy, but do not directly inhibit iodine trapping [2]. *Methimazole* - **Methimazole** is a **thionamide** drug that primarily inhibits the enzyme **thyroid peroxidase**. - This prevents the **organification of iodide** (incorporation of iodine into tyrosine residues) and the **coupling of iodotyrosines** (forming T3 and T4), not the initial trapping of iodine.

Q: Which of the following is the longest acting glucocorticoid?

Dexamethasone. ***Correct: Dexamethasone*** - **Dexamethasone** is a long-acting glucocorticoid with a **biological half-life of 36–72 hours**, making it the longest acting among the options provided - Its prolonged action is due to its **high affinity for the glucocorticoid receptor** and relatively slow metabolism - Provides sustained anti-inflammatory and immunosuppressive effects *Incorrect: Prednisone* - **Prednisone** is an intermediate-acting glucocorticoid with a biological half-life of 12-36 hours - Requires metabolism in the liver to its active form, prednisolone - Duration of action is significantly shorter than dexamethasone *Incorrect: Prednisolone* - **Prednisolone** is the active form of prednisone, with a similar intermediate duration of action (12-36 hours) - Primarily used when liver conversion of prednisone is impaired - Does not possess the extended duration of action characteristic of dexamethasone *Incorrect: Cortisone* - **Cortisone** is a short-acting glucocorticoid with a biological half-life of 8-12 hours - It is a prodrug that needs to be converted to **hydrocortisone** (cortisol) in the liver to become active - Has the shortest duration among all options

Q: Which of the following is the most potent topical corticosteroid?

Clobetasol propionate. ***Clobetasol propionate*** - **Clobetasol propionate** is recognized as one of the most potent **Class I topical corticosteroids**, used for severe inflammatory skin conditions. - Its high potency allows for effective suppression of severe inflammation and pruritus, but also carries a greater risk of **adverse effects** with prolonged use. *Triamcinolone acetonide* - **Triamcinolone acetonide** is a **medium-potency** topical corticosteroid (Class IV-V), less potent than clobetasol propionate. - It is commonly used for moderate inflammatory skin conditions, such as eczema and psoriasis, but not for severe cases requiring maximum potency. *Hydrocortisone acetate* - **Hydrocortisone acetate** is a **low-potency** topical corticosteroid (Class VII), making it the least potent option listed. - It's often used for mild inflammatory conditions, sensitive areas like the face, or for less severe conditions requiring minimal corticosteroid strength. *Betamethasone valerate* - **Betamethasone valerate** is a **medium-to-high potency** topical corticosteroid (Class III-V), placing it among stronger corticosteroids but still less potent than clobetasol propionate. - It is effective for moderate to severe inflammatory skin conditions but does not reach the highest level of potency demonstrated by clobetasol.

Q: Which of the following reduces the efficacy of oral contraceptives?

Griseofulvin. ***Griseofulvin*** - **Griseofulvin** is an antifungal agent known to induce liver enzymes, specifically the **cytochrome P450 system**. - Enzyme induction accelerates the metabolism and clearance of **oral contraceptives**, leading to lower plasma concentrations and reduced efficacy. *Erythromycin* - **Erythromycin** is a macrolide antibiotic that typically inhibits liver enzymes rather than inducing them. - While it can interfere with the metabolism of some drugs, it usually **increases** rather than decreases the plasma levels of co-administered medications, and is not known to reduce oral contraceptive efficacy. *Disulfiram* - **Disulfiram** is used to treat chronic alcoholism and inhibits aldehyde dehydrogenase. - It does not significantly interact with the metabolism of **oral contraceptives** via the cytochrome P450 system or other mechanisms that would reduce their efficacy. *Cimetidine* - **Cimetidine** is an H2 receptor antagonist that is known to inhibit cytochrome P450 enzymes. - This inhibition would likely **increase** the plasma concentration of drugs metabolized by these enzymes, such as oral contraceptives, rather than reducing their efficacy.

Question 1

Which of the following is a benzylisoquinoline muscle relaxant?

Accepted Answer

Doxacurium

Answer

Rocuronium

Answer

Pancuronium

Answer

Vecuronium

Question 2

Which medication increases insulin secretion from beta cells?

Accepted Answer

Repaglinide

Answer

Metformin

Answer

Pioglitazone

Answer

Pramlintide

Question 3

Which of the following antidiabetic drugs (other than insulin) is indicated as adjunct therapy for the management of both type I and type II diabetes mellitus?

Accepted Answer

Pramlintide

Answer

Sulphonylureas

Answer

Metformin

Answer

Acarbose

Question 4

Which of the following statements about sitagliptin is false?

Accepted Answer

Cannot be used orally

Answer

Used in type II diabetes mellitus

Answer

Used in combination with other oral hypoglycemic agents

Answer

All of the above statements are true

Question 5

What is a potential risk associated with the use of thiazolidinediones in the treatment of type 2 diabetes?

Accepted Answer

Heart failure

Answer

Pulmonary fibrosis

Answer

Myocarditis

Answer

Renal dysfunction

Question 6

What conditions is Metformin primarily used to treat?

Accepted Answer

Both Type 2 Diabetes and Polycystic Ovary Syndrome (PCOS)

Answer

Only Type 2 Diabetes

Answer

Only Polycystic Ovary Syndrome (PCOS)

Answer

Pregnancy Induced Hypertension

Question 7

Which of the antithyroid drugs inhibits iodine trapping?

Accepted Answer

Thiocyanates

Answer

Radioactive iodine

Answer

Iodides

Answer

Methimazole

Question 8

Which of the following is the longest acting glucocorticoid?

Accepted Answer

Dexamethasone

Answer

Prednisone

Answer

Prednisolone

Answer

Cortisone

Question 9

Which of the following is the most potent topical corticosteroid?

Accepted Answer

Clobetasol propionate

Answer

Triamcinolone acetonide

Answer

Hydrocortisone acetate

Answer

Betamethasone valerate

Question 10

Which of the following reduces the efficacy of oral contraceptives?

Accepted Answer

Griseofulvin

Answer

Disulfiram

Answer

Erythromycin

Answer

Cimetidine

NEET-PG 2013 — Pharmacology