NEET-PG 2017 - Pharmacology PYQs Practice Questions

Q: A 65-year-old patient of dilated cardiomyopathy was prescribed 1 mg warfarin tablet for sustained atrial fibrillation. The chemist however gave him 2 mg tablets by mistake which resulted in him developing hemorrhagic complications (bleeding). CT scan is performed. This is which kind of ADR? (Recent NEET Pattern 2016-17) Warfarin Sodium Tablets, USP Crystalline 2 mg Protect from light

Type A. ***Type A*** - This is an **exaggerated pharmacological effect** of warfarin due to a higher than intended dose, leading to excessive anticoagulation and subsequent **hemorrhagic stroke** (bleeding in the brain). - Type A ADRs are **predictable** based on the known pharmacology of the drug and are dose-dependent. *Type B* - Type B ADRs are **unpredictable**, idiosyncratic reactions that are not directly related to the pharmacological action of the drug (e.g., allergic reactions). - They are typically **dose-independent** and often occur in a small subset of the population. *Type C* - Type C ADRs are associated with **long-term exposure** to a drug, leading to chronic effects or tolerance. - Examples include drug dependence or adrenal suppression from prolonged corticosteroid use. *Type D* - Type D ADRs are also related to **delayed effects** of drug exposure, such as carcinogenesis or teratogenesis. - These effects may not manifest until months or years after the drug was taken. [Practice more Pharmacology PYQs on OnCourse]

Q: The effect of both drugs given together on the blood pressure of a patient was evaluated in comparison with the effect of individual drugs on BP. The following curve represents: (Recent NEET Pattern 2016-17)

Synergism. ***Synergism*** - The graph shows that the effect of drugs A and B when given together (A+B) is significantly **greater than the sum of their individual effects**. - This amplified effect, where the combined response is more than the simple addition of individual responses, is the definition of **synergism** (also called potentiation or supra-additive effect). *Summation* - Summation occurs when the **combined effect** of two drugs is **equal to the arithmetic sum** of their individual effects. - In the depicted graph, the peak effect of A+B is clearly much higher than the sum of the peaks of A and B individually, ruling out simple summation. *Additive effects* - Additive effects are synonymous with summation, meaning the combined effect is precisely the sum of individual effects. - The graph demonstrates a response that **exceeds a simple additive effect**, indicating a synergistic interaction rather than mere additive action. *Antagonism* - **Antagonism** occurs when one drug reduces or blocks the effect of another drug, resulting in a combined effect that is **less than the sum** of individual effects. - In the depicted graph, the combined effect (A+B) clearly shows enhancement rather than reduction, ruling out antagonism. [Practice more Pharmacology PYQs on OnCourse]

Q: Drug A is epinephrine and drug B is cocaine. The effect of both drugs given together on the blood pressure of a patient was evaluated in comparison with effect of individual drugs on BP. The following curve represents:

Synergism. ***Synergism*** - **Synergism** occurs when the combined effect of two drugs is significantly greater than the sum of their individual effects. In the provided graph, the peak blood pressure with drugs A+B is notably higher than the sum of the peaks for A and B administered separately. - Epinephrine (Drug A) is a **vasoconstrictor**, and cocaine (Drug B) **inhibits norepinephrine reuptake**, potentiating epinephrine's effects by increasing synaptic levels of catecholamines. This leads to a much stronger combined increase in blood pressure than expected from simple addition. *Summation* - **Summation** implies that the combined effect of two drugs is equal to the sum of their individual effects. - The graph clearly shows that the combined effect (A+B) produces a blood pressure response that is much greater than simply adding the individual responses of A and B, ruling out summation. *Additive effects* - **Additive effects** are a type of summation where the combined effect of two or more drugs is numerically equal to the arithmetic sum of their individual effects. - Similar to summation, this option is incorrect because the observed combined effect of A and B is significantly *more* than the mathematical sum of their separate effects, indicating potentiation rather than simple additivity. *Antagonism* - **Antagonism** occurs when one drug reduces or blocks the effect of another drug. - This is incorrect because the graph shows that the combined administration of epinephrine and cocaine produces a *greater* blood pressure response, not a reduced one. Antagonism would result in a combined effect less than expected or less than either drug alone. [Practice more Pharmacology PYQs on OnCourse]

Q: Which anti-epileptic drug marked X will act at the site shown?

Tiagabine. ***Tiagabine*** - The image shows the reuptake of **GABA** from the synaptic cleft, and "X" points to this reuptake mechanism. Tiagabine is an anti-epileptic drug that acts by **inhibiting GABA reuptake**. - By inhibiting GABA reuptake, tiagabine increases the concentration of **GABA** in the synapse, enhancing its inhibitory effects and reducing neuronal excitability. *Valproate* - Valproate has multiple mechanisms of action, including inhibiting **GABA transaminase** (GABA-T) which leads to increased GABA levels, but it does not directly act on GABA reuptake. - It also blocks voltage-gated **sodium channels** and T-type calcium channels. *Gabapentin* - Gabapentin is an analogue of GABA but does not act directly on GABA receptors or GABA reuptake. - Its mechanism of action is primarily by binding to the **α2δ subunit of voltage-gated calcium channels**, reducing calcium influx and neurotransmitter release. *Vigabatrin* - Vigabatrin primarily works by irreversibly inhibiting **GABA transaminase (GABA-T)**, the enzyme responsible for the breakdown of GABA. - This leads to a persistent increase in **GABA** levels in the brain, thereby enhancing inhibitory neurotransmission. [Practice more Pharmacology PYQs on OnCourse]

Q: Which anti-epileptic drug marked X will act at the site shown?

Tiagabine. ***Tiagabine*** - The image shows site 'X' as a **GABA reuptake transporter** that actively removes GABA from the synaptic cleft back into the presynaptic neuron or glial cells - **Tiagabine** specifically inhibits **GABA reuptake transporters (GAT-1)**, thereby increasing GABA concentration in the synaptic cleft and enhancing its inhibitory effect - This is the mechanism directly targeting the site shown in the diagram *Vigabatrin* - Irreversible inhibitor of **GABA transaminase (GABA-T)**, the enzyme responsible for catabolizing GABA - Acts intracellularly to prevent GABA breakdown, not at the synaptic reuptake transporter shown - Different mechanism from the site depicted *Gabapentin* - GABA analog but does not bind to GABA receptors or interfere with GABA reuptake - Primary mechanism involves modulating **voltage-gated calcium channels (α2δ subunit)**, reducing excitatory neurotransmitter release - Does not act at GABA transporters *Rufinamide* - Prolongs the inactive state of **voltage-dependent sodium channels**, reducing neuronal excitability - Mechanism is distinct from GABA reuptake or metabolism - Does not act at the site shown in the diagram [Practice more Pharmacology PYQs on OnCourse]

Question 1

A 65-year-old patient of dilated cardiomyopathy was prescribed 1 mg warfarin tablet for sustained atrial fibrillation. The chemist however gave him 2 mg tablets by mistake which resulted in him developing hemorrhagic complications (bleeding). CT scan is performed. This is which kind of ADR? (Recent NEET Pattern 2016-17) Warfarin Sodium Tablets, USP Crystalline 2 mg Protect from light

Accepted Answer

Type A

Answer

Type B

Answer

Type C

Answer

Type D

Question 2

The effect of both drugs given together on the blood pressure of a patient was evaluated in comparison with the effect of individual drugs on BP. The following curve represents: (Recent NEET Pattern 2016-17)

Accepted Answer

Synergism

Answer

Summation

Answer

Additive effects

Answer

Antagonism

Question 3

Drug A is epinephrine and drug B is cocaine. The effect of both drugs given together on the blood pressure of a patient was evaluated in comparison with effect of individual drugs on BP. The following curve represents:

Accepted Answer

Synergism

Answer

Summation

Answer

Additive effects

Answer

Antagonism

Question 4

Which anti-epileptic drug marked X will act at the site shown?

Accepted Answer

Tiagabine

Answer

Vigabatrin

Answer

Valproate

Answer

Gabapentin

Question 5

Which anti-epileptic drug marked X will act at the site shown?

Accepted Answer

Tiagabine

Answer

Vigabatrin

Answer

Gabapentin

Answer

Rufinamide

Question 6

The application of the following product can lead to development of: (Recent NEET Pattern 2016-17)

Accepted Answer

Methemoglobinemia

Answer

Seizures

Answer

Depression

Answer

Hypertension

NEET-PG 2017 — Pharmacology