NEET-PG 2019 - Pharmacology PYQs Practice Questions

Q: Carbapenem with the maximum seizure risk is:

Imipenem. ***Imipenem*** - **Imipenem** is primarily associated with a higher risk of seizures due to its ability to inhibit **GABAergic neurotransmission** in the central nervous system. - This effect is dose-dependent and more pronounced in patients with **renal impairment** or pre-existing CNS disorders, where drug accumulation occurs. *Meropenem* - While meropenem can also cause seizures, its **GABA antagonistic effect** is less potent than imipenem, resulting in a lower incidence of this adverse event. - It is generally considered safer than imipenem for patients at risk of seizures. *Ertapenem* - Ertapenem has an even lower propensity for causing seizures compared to imipenem and meropenem. - It is often preferred in outpatient settings due to its **once-daily dosing** and favorable safety profile regarding CNS adverse effects. *Doripenem* - Doripenem also has a **low seizure potential**, similar to meropenem and ertapenem. - Its **pharmacokinetic profile** and CNS penetration differ, but it is not associated with the same high risk as imipenem. [Practice more Pharmacology PYQs on OnCourse]

Q: Which of the following best demonstrates the variability in drug responsiveness among individuals?

Quantal Dose Response Curve. ***Quantal Dose Response Curve*** - A **quantal dose-response curve** plots the percentage of individuals exhibiting a discrete, all-or-none effect against the log dose of a drug. - This curve directly illustrates the **variability in drug responsiveness** within a population by showing the range of doses required to produce a specific effect in different individuals. *Efficacy* - **Efficacy** refers to the maximum effect a drug can produce, regardless of the dose. - While efficacy is an important pharmacological parameter, it describes the drug's overall therapeutic potential, not the **individual variability** in response. *Potency* - **Potency** is a measure of the amount of drug needed to produce an effect of given intensity. - It relates to the absolute dose required for a particular effect but does not directly demonstrate the **inter-individual differences** in biological response. *Graded Dose Response Curve* - A **graded dose-response curve** depicts the relationship between the dose of a drug and the **magnitude of the effect** in a **single biological unit** (e.g., an individual, a tissue, or a cell). - This curve reflects the relationship between drug concentration and effect intensity, but not the **variability in response among different individuals** in a population. [Practice more Pharmacology PYQs on OnCourse]

Q: What is the drug of choice (DOC) for a scorpion sting bite?

Prazosin. ***Prazosin*** - **Prazosin** is an **alpha-1 adrenergic antagonist** that effectively counteracts the symptoms of scorpion envenomation, particularly **autonomic hyperactivity** like hypertension and tachycardia. - It works by blocking the effects of norepinephrine released by the scorpion venom, helping to stabilize vital signs and reduce cardiovascular complications. *EDTA* - **EDTA (ethylenediaminetetraacetic acid)** is a **chelating agent** primarily used to treat **heavy metal poisoning**, such as lead or mercury. - It binds to metal ions, forming a stable complex that can then be excreted from the body; it has no role in scorpion envenomation. *Neostigmine* - **Neostigmine** is an **acetylcholinesterase inhibitor** used to treat conditions like myasthenia gravis or to reverse the effects of neuromuscular blocking agents. - It increases acetylcholine levels at the neuromuscular junction; it is not indicated for the management of scorpion stings. *N-acetylcysteine* - **N-acetylcysteine (NAC)** is primarily used as an **antidote for acetaminophen overdose** and as a mucolytic agent in respiratory conditions. - It replenishes glutathione stores, helping to detoxify harmful metabolites; it has no direct role in treating scorpion venom effects. [Practice more Pharmacology PYQs on OnCourse]

Q: Which fluoroquinolone has the maximum bioavailability?

Levofloxacin. ***Levofloxacin*** - **Levofloxacin** exhibits high oral bioavailability, approximately 99%, meaning nearly all of the administered dose reaches systemic circulation [1]. - This high bioavailability allows for seamless transition from intravenous to oral administration without significant changes in drug exposure [1]. *Moxifloxacin* - **Moxifloxacin** has a high bioavailability of approximately 90%, which is slightly lower than levofloxacin's almost complete absorption [1]. - While excellent, it is not the absolute highest among fluoroquinolones. *Gatifloxacin* - **Gatifloxacin** has good oral bioavailability, around 96%, but it is still generally considered slightly less than that of levofloxacin [1]. - This difference, though small, makes levofloxacin the one with the highest overall bioavailability. *Ciprofloxacin* - **Ciprofloxacin** has the lowest oral bioavailability among the listed fluoroquinolones, ranging from 70% to 80% [1]. - Its absorption can be significantly impaired by co-administration with multivalent cations, leading to reduced systemic concentrations. [Practice more Pharmacology PYQs on OnCourse]

Question 1

Which of the following statements is true regarding a fixed-dose combination of drugs?

Accepted Answer

The adverse effect of one drug may be mitigated by the other drug.

Answer

The dose of one drug can be adjusted independently.

Answer

Adverse effects can be attributed solely to one drug.

Answer

Combining two drugs with different pharmacokinetics is straightforward.

Question 2

Carbapenem with the maximum seizure risk is:

Accepted Answer

Imipenem

Answer

Meropenem

Answer

Doripenem

Answer

Ertapenem

Question 3

Which of the following best demonstrates the variability in drug responsiveness among individuals?

Accepted Answer

Quantal Dose Response Curve

Answer

Potency

Answer

Efficacy

Answer

Graded Dose Response Curve

Question 4

What is the drug of choice (DOC) for a scorpion sting bite?

Accepted Answer

Prazosin

Answer

EDTA

Answer

Neostigmine

Answer

N-acetylcysteine

Question 5

Which fluoroquinolone has the maximum bioavailability?

Accepted Answer

Levofloxacin

Answer

Gatifloxacin

Answer

Ciprofloxacin

Answer

Moxifloxacin

Question 6

Which of the following drugs is used in SIADH?

Accepted Answer

Tolvaptan

Answer

Desmopressin

Answer

Terlipressin

Answer

Von Willebrand factor

Question 7

Variation in sensitivity of response to different doses of a drug in different individuals is obtained from?

Accepted Answer

Dose-response relationship

Answer

Therapeutic index

Answer

Bioavailability

Answer

Phase 1 clinical trials

Question 8

Carbapenem which has a tendency to cause maximum seizures?

Accepted Answer

Imipenem

Answer

Ertapenem

Answer

Doripenem

Answer

Meropenem

Question 9

Which among the following is most probable reason for preference of Cisatracurium over atracurium?

Accepted Answer

Decreased histamine release

Answer

Increased histamine release

Answer

Decreased CNS toxicity

Answer

Due to elimination by non-specific plasma esterases

Question 10

Imipenem, a newer antibiotic with a broad antibacterial spectrum, is co-administered with cilastatin. What is the primary reason for this combination?

Accepted Answer

Cilastatin prevents the degradation of imipenem by inhibiting an enzyme in the kidneys.

Answer

Cilastatin enhances the gastrointestinal absorption of imipenem.

Answer

Cilastatin inhibits the beta-lactamase enzyme that degrades imipenem.

Answer

The combination of antibiotics is synergistic against Pseudomonas species.

NEET-PG 2019 — Pharmacology