FMGE 2018 - Pharmacology PYQs Practice Questions

Q: Exenatide is a new drug used in diabetes mellitus. Mechanism of action of this drug is:-

Release of insulin acting as agonist of GLP-1 receptors. ***Release of insulin acting as agonist of GLP-1 receptors*** - **Exenatide** is a **glucagon-like peptide-1 (GLP-1) receptor agonist**, mimicking the action of endogenous GLP-1. - This leads to glucose-dependent **insulin release**, suppression of **glucagon secretion**, delayed **gastric emptying**, and increased **satiety**, all contributing to improved glycemic control. *Inhibition of DPP-4* - This mechanism describes the action of **DPP-4 inhibitors** (e.g., sitagliptin, saxagliptin), which prevent the breakdown of endogenous GLP-1 and other **incretin hormones**. - While both GLP-1 agonists and DPP-4 inhibitors target the incretin system, exenatide directly acts as an agonist, rather than preventing breakdown. *Inhibiting intestinal absorption of carbohydrates* - This mechanism describes drugs like **alpha-glucosidase inhibitors** (e.g., acarbose, miglitol), which delay carbohydrate absorption from the gut. - Exenatide's primary action is not on carbohydrate absorption but rather on pancreatic hormone secretion and gastric emptying. *Stimulation of PPAR-gamma* - This mechanism describes **thiazolidinediones** (TZDs) like pioglitazone and rosiglitazone, which enhance **insulin sensitivity** by acting on **peroxisome proliferator-activated receptor-gamma (PPAR-gamma)** in adipose tissue. - Exenatide belongs to a different class of antidiabetic drugs with a distinct mechanism of action. [Practice more Pharmacology PYQs on OnCourse]

Q: Shortest-acting muscle relaxant is:

Succinylcholine. ***Correct: Succinylcholine*** - **Succinylcholine** is a depolarizing neuromuscular blocker with a rapid onset and a very short duration of action, typically **5-10 minutes**, due to its rapid hydrolysis by **plasma pseudocholinesterase**. - Its ultrashort action makes it ideal for **rapid sequence intubation** and other procedures requiring brief muscle relaxation. *Incorrect: Atracurium* - **Atracurium** is an intermediate-acting nondepolarizing muscle relaxant with a duration of action of approximately **20-35 minutes**. - Its metabolism occurs via Hoffman elimination and ester hydrolysis, making it suitable for patients with **renal or hepatic dysfunction**. *Incorrect: Tubocurarine* - **Tubocurarine** is a long-acting nondepolarizing muscle relaxant that is now rarely used due to its significant adverse effects, including **histamine release** and ganglion blockade. - Its duration of action can be **60-120 minutes**. *Incorrect: Pancuronium* - **Pancuronium** is a long-acting nondepolarizing muscle relaxant with a duration of action of **60-90 minutes**. - It is eliminated primarily by the **kidneys**, making its duration prolonged in patients with **renal impairment**. [Practice more Pharmacology PYQs on OnCourse]

Q: Pharmacodynamics deals with:-

Mechanism of action of a drug. Detailed study of the **Mechanism of action of a drug** [1][2] - **Pharmacodynamics** describes what the **drug does to the body**, including its **molecular targets** and biochemical effects [3]. - This involves the study of the drug's mechanisms to produce its therapeutic or toxic effects [2]. *Latency of onset* - **Latency of onset** refers to the time it takes for a drug to start producing its effects, which is a pharmacokinetic rather than a pharmacodynamic parameter. - It deals with the drug's absorption and distribution rather than its interaction with the body once it reaches its site of action. *Transport of drug across the biological membranes* - The **transport of drugs across biological membranes** is a key aspect of **pharmacokinetics**, specifically absorption and distribution [1]. - This process determines how much drug reaches its target site, not how it interacts with the target. *Mode of excretion of a drug* - The **mode of excretion** of a drug (e.g., renal, hepatic) falls under **pharmacokinetics**, addressing how the body gets rid of the drug. - This process influences the drug's duration of action and elimination half-life, not its mechanism of action. [Practice more Pharmacology PYQs on OnCourse]

Q: Therapeutic index of a drug is an indicator of:-

Safety. ***Safety*** - The **therapeutic index (TI)** is a ratio comparing the **toxic dose (TD50)** to the **effective dose (ED50)**: TI = TD50/ED50. - It indicates the **margin of safety** of a drug—the wider the margin between therapeutic and toxic doses, the safer the drug. - A **high therapeutic index** means greater safety; a **low therapeutic index** means the drug has a narrow safety margin. *Potency* - **Potency** refers to the amount of drug needed to produce a given effect, represented by the **ED50**. - The therapeutic index is a **ratio**, not a measure of potency alone. - A highly potent drug can still have a narrow therapeutic index if its toxic dose is close to its effective dose. *Efficacy* - **Efficacy** describes the **maximum therapeutic effect** a drug can produce, irrespective of dose. - The therapeutic index does not quantify maximum effect but rather the **safety margin** within which therapeutic effects can be achieved. *All of these* - While potency and efficacy are important drug properties, the therapeutic index **specifically indicates safety**. - TI is not a composite measure of all drug properties—it is exclusively a safety parameter. [Practice more Pharmacology PYQs on OnCourse]

Q: Shortest acting local anaesthetic

Chloroprocaine. ***Chloroprocaine*** - **Chloroprocaine** is known for its rapid onset and very **short duration of action**, typically lasting 30-60 minutes, due to its **rapid hydrolysis** by plasma and liver esterases. - Its quick metabolism makes it suitable for short procedures where a brief blockade is desired, minimizing the risk of systemic toxicity. *Dibucaine* - **Dibucaine** is a local anesthetic with a **long duration of action**, typically 2 to 4 hours, which is much longer than chloroprocaine. - It is used topically and in spinal anesthesia, but its prolonged effect makes it unsuitable as the shortest-acting option. *Procaine* - **Procaine** is an ester-type local anesthetic with a relatively **short duration of action** (approximately 30-60 minutes), but it is generally longer than that of chloroprocaine. - It was one of the first synthetic local anesthetics and is less potent and shorter-acting than many modern agents. *Cocaine* - **Cocaine** has a moderate duration of action as a local anesthetic, typically lasting 60-90 minutes, which is longer than chloroprocaine. - While it is a potent local anesthetic and vasoconstrictor, its high abuse potential and systemic side effects limit its clinical use, mainly to topical application in otolaryngology. [Practice more Pharmacology PYQs on OnCourse]

Question 1

Exenatide is a new drug used in diabetes mellitus. Mechanism of action of this drug is:-

Accepted Answer

Release of insulin acting as agonist of GLP-1 receptors

Answer

Inhibiting intestinal absorption of carbohydrates

Answer

Stimulation of PPAR-gamma

Answer

Inhibition of DPP-4

Question 2

Shortest-acting muscle relaxant is:

Accepted Answer

Succinylcholine

Answer

Atracurium

Answer

Tubocurarine

Answer

Pancuronium

Question 3

Pharmacodynamics deals with:-

Accepted Answer

Mechanism of action of a drug

Answer

Latency of onset

Answer

Transport of drug across the biological membranes

Answer

Mode of excretion of a drug

Question 4

Therapeutic index of a drug is an indicator of:-

Accepted Answer

Safety

Answer

All of these

Answer

Potency

Answer

Efficacy

Question 5

Shortest acting local anaesthetic

Accepted Answer

Chloroprocaine

Answer

Dibucaine

Answer

Procaine

Answer

Cocaine

Question 6

The drug that causes fall in elderly patients with postural hypotension is:-

Accepted Answer

Prazosin

Answer

Acarbose

Answer

Nor-adrenaline

Answer

Metformin

Question 7

In the management of diabetes mellitus, lactic acidosis is caused by which of the following?

Accepted Answer

Metformin

Answer

Pioglitazone

Answer

Glipizide

Answer

Tolbutamide

Question 8

Prophylactic dose of Oseltamivir for infants (3-11 months) is?

Accepted Answer

3 mg/kg/day

Answer

5 mg/kg/day

Answer

1 mg/kg/day

Answer

7 mg/kg/day

Question 9

Which of the following drugs is a direct inhibitor of clotting factor Xa?

Accepted Answer

Apixaban

Answer

Argatroban

Answer

Fondaparinux

Answer

Aspirin

Question 10

True for lithium:

Accepted Answer

Narrow therapeutic index

Answer

Can be given safely in renal dysfunction

Answer

Protein bound

Answer

Delayed absorption

FMGE 2018 — Pharmacology