NEET-PG 2013 - Pharmacology Practice Questions

Q: Which drug is most commonly associated with causing fixed drug eruptions?

Sulfonamide. ***Sulfonamide*** - **Sulfonamides**, particularly **sulfamethoxazole-trimethoprim**, are frequently implicated in causing fixed drug eruptions. - A fixed drug eruption characteristically recurs at the **same cutaneous site** each time the offending drug is administered. *Aminoglycoside* - **Aminoglycosides** are broad-spectrum antibiotics known for potential **ototoxicity** and **nephrotoxicity**. - While they can cause various adverse reactions, fixed drug eruptions are **not a common association** with this drug class. *Erythromycin* - **Erythromycin** is a macrolide antibiotic primarily associated with **gastrointestinal side effects**, such as nausea and abdominal cramping. - Although drug eruptions can occur, fixed drug eruptions are **not typically linked** to erythromycin. *None of the options* - This option is incorrect because **sulfonamides** are well-documented causes of fixed drug eruptions. - Therefore, there is a specific drug class listed that is strongly associated with this condition.

Q: Which drug would be most appropriate for treating a patient with suspected chlamydia-gonorrhea coinfection?

Doxycycline. ***Doxycycline*** - **Doxycycline** is a highly effective treatment for **chlamydia**, and its broad-spectrum activity also covers potential **gonorrhea coinfection** when used as part of a dual therapy regimen. - It is often prescribed alongside a **single dose of ceftriaxone** for presumed gonorrhea coinfection, as ceftriaxone targets gonorrhea while doxycycline targets chlamydia. *Ciprofloxacin* - **Ciprofloxacin** is a **fluoroquinolone** antibiotic, which is generally not recommended as first-line treatment for uncomplicated **gonorrhea** or **chlamydia** due to increasing resistance. - It has activity against *Neisseria gonorrhoeae*, but its effectiveness against *Chlamydia trachomatis* is suboptimal compared to macrolides or tetracyclines. *Norfloxacin* - **Norfloxacin** is another **fluoroquinolone** with a narrower spectrum of activity than ciprofloxacin and is primarily used for **urinary tract infections**. - It has **poor efficacy against chlamydia** and is not a recommended treatment for either organism in this context. *Nalidixic acid* - **Nalidixic acid** is a first-generation **quinolone** with a very limited spectrum, used mainly for **gram-negative urinary tract infections**. - It has **no significant activity against chlamydia** or gonorrhea and is therefore inappropriate for treating this suspected coinfection.

Q: The mechanism by which ergometrine stops postpartum hemorrhage is that it:

Increases tone of uterine muscle. ***Increases tone of uterine muscle*** - **Ergometrine** is an **ergot alkaloid** that directly stimulates **uterine smooth muscle contractions**. - These sustained contractions lead to **compression of blood vessels within the myometrium**, thereby reducing blood flow and controlling **postpartum hemorrhage**. *Causes vasoconstriction of uterine arteries* - While ergometrine does have some generalized **vasoconstrictive effects**, its primary mechanism of action in controlling postpartum hemorrhage is not mainly through direct vasoconstriction of large uterine arteries. - The crucial effect is the **sustained uterine contraction** which mechanically occludes blood vessels, rather than chemical constriction of the vessels themselves. *Induces platelet aggregation* - Ergometrine does not primarily act by inducing **platelet aggregation**; this is a function of specific clotting factors and platelet activators. - Its therapeutic effect against hemorrhage is mediated through its action on **uterine contractility**, not on the cellular components of coagulation. *Promotes coagulation* - Ergometrine does not directly promote the **coagulation cascade** or enhance the formation of fibrin clots. - Its mechanism of action is distinct from agents that affect intrinsic or extrinsic pathways of coagulation.

Q: Depot preparations are administered by ?

Both subcutaneous and intramuscular route. ***Both subcutaneous and intramuscular route*** - **Depot preparations** are designed for **sustained release** of medication over an extended period - This is achieved by forming a 'depot' in the tissue, often facilitated by a viscous vehicle or sparingly soluble form of the drug - Both **subcutaneous** and **intramuscular** tissues can sustain depot formulations effectively - **SC depot examples:** Insulin glargine, contraceptive implants (Nexplanon), leuprolide acetate - **IM depot examples:** Haloperidol decanoate, medroxyprogesterone acetate (Depo-Provera), paliperidone palmitate, long-acting risperidone *Subcutaneous route* - While some **depot preparations** are administered **subcutaneously**, it is not the *only* route for all depot formulations - The **subcutaneous tissue** offers relatively low blood flow, suitable for slow absorption - Alone, this option is incomplete as many depot preparations require IM administration *Intramuscular route* - Many **depot preparations** are given **intramuscularly** due to the muscle tissue's vascularity and tissue volume - The **muscle tissue** provides an excellent site for drug reservoir formation - Alone, this option is incomplete as some depot preparations are given subcutaneously *Intravenous route* - **Intravenous administration** is used for immediate and rapid drug delivery directly into the bloodstream - This route is **unsuitable for depot preparations** which require sustained release over time - No 'depot' can be formed with IV route as the drug is immediately diluted and distributed throughout the body

Q: True about MDMA:

Ecstasy is another name for it. Ecstasy is another name for it - MDMA (3,4-methylenedioxymethamphetamine) is widely known by its street name, Ecstasy [1]. - This name refers to its profound empathogenic effects and sense of well-being it often induces. It is a cocaine congener - MDMA is an amphetamine derivative and acts primarily on serotonin, dopamine, and norepinephrine systems, distinct from cocaine's primary action as a reuptake inhibitor [1], [2]. - While both MDMA and cocaine are stimulants, their chemical structures and primary mechanisms of action are different; MDMA is a substituted amphetamine [1]. Methadone is used to treat withdrawal symptoms - Methadone is an opioid agonist primarily used in the management of opioid dependence and withdrawal symptoms [3]. - MDMA withdrawal symptoms are typically managed with supportive care, focusing on symptom relief and psychological support, as there is no specific pharmacological treatment like methadone for MDMA withdrawal [3]. Causes parkinsonism like syndrome - While MDMA can cause neurotoxicity, particularly affecting serotonergic neurons, it is not typically associated with a direct parkinsonism-like syndrome [2]. - Parkinsonism is primarily linked to dopaminergic system damage, often seen with certain neuroleptics or drugs like MPTP, not MDMA.

Q: Which of the following is used in the second-line management of strychnine poisoning?

Barbiturates. ***Barbiturates*** - As a **second-line treatment**, barbiturates like phenobarbital are used to control **refractory seizures** and muscle spasms in strychnine poisoning when benzodiazepines are insufficient. - They enhance the effect of **GABA**, leading to central nervous system depression and muscle relaxation. *Physostigmine* - This is an **acetylcholinesterase inhibitor** and is primarily used to reverse the anticholinergic effects of certain poisonings, not strychnine. - It would worsen seizures by increasing **acetylcholine**, which can cause tremors and convulsions. *Naloxone* - Naloxone is an **opioid antagonist** used to reverse opioid overdose, which presents with respiratory depression and pinpoint pupils. - It has no role in treating strychnine poisoning, which primarily causes **muscle spasms** and seizures. *Diazepam* - Diazepam, a **benzodiazepine**, is the **first-line treatment** for seizures and muscle spasms in strychnine poisoning. - It works by enhancing the effects of **GABA** at the GABA-A receptor, thereby reducing neuronal excitability.

Q: Knockout drops are:

Chloral hydrate. ***Chloral hydrate*** - **Chloral hydrate** is a sedative-hypnotic substance historically used as "knockout drops" due to its quick action in inducing sleep or unconsciousness. - Its use has largely been replaced by safer alternatives due to its narrow therapeutic index and potential for respiratory depression and cardiac arrhythmias. *Kerosene* - **Kerosene** is a flammable hydrocarbon liquid primarily used as fuel or solvent, not as a sedative or hypnotic agent. - Ingestion of kerosene is highly toxic and can cause chemical pneumonitis and gastrointestinal irritation. *Paraldehyde* - **Paraldehyde** is an older sedative and hypnotic drug, but it is not typically referred to as "knockout drops." - It has a very pungent odor and taste, which would make surreptitious administration difficult, and is generally avoided in modern medical practice. *Turpentine* - **Turpentine** is a distillate of pine resin used as a solvent or cleaner, and historically as a liniment or anthelminthic. - It is highly toxic if ingested and can cause severe gastrointestinal distress, kidney damage, and central nervous system depression, but it is not a sedative-hypnotic.

Q: Acrodynia, or Pink disease, occurs in poisoning with which of the following substances?

Mercury. ***Mercury*** - **Acrodynia**, also known as **Pink disease**, is a rare and severe form of **mercury poisoning**, primarily affecting infants and young children. - Key symptoms include **pinkish-red rash** on the hands and feet, hypertension, irritability, profuse sweating, and muscle weakness. *Lead* - **Lead poisoning** typically presents with symptoms such as **abdominal pain**, constipation, developmental delay, and a **lead line on the gums**. - It does not cause the characteristic rash or other symptoms associated with acrodynia. *Thallium* - **Thallium poisoning** is known for causing **hair loss (alopecia)**, excruciating neuropathic pain, gastrointestinal disturbances, and neurological symptoms. - While it is a neurotoxic heavy metal, its clinical picture is distinct from acrodynia. *Arsenic* - **Arsenic poisoning** can manifest with dermatological signs like **hyperpigmentation** and **hyperkeratosis**, as well as gastrointestinal and neurological symptoms. - It does not produce the pinkish rash, irritability, or hypertension typical of acrodynia.

Q: Oximes are contraindicated in which poisoning:

Carbamate. ***Carbamate*** - Traditionally, oximes were considered **contraindicated** in carbamate poisoning based on concerns they could worsen the **cholinergic crisis** by reactivating carbamylated acetylcholinesterase. - Carbamates spontaneously **decarbamylate** from acetylcholinesterase within minutes to hours, so their inhibition is typically **short-lived and reversible**. - **Clinical relevance**: While modern evidence suggests oximes are more likely **ineffective** rather than harmful in carbamate poisoning, they are generally **not recommended** as they provide no therapeutic benefit. For exam purposes, particularly in historical contexts (NEET 2012-2013), carbamate poisoning is the answer for oxime contraindication. *Diazinon* - Diazinon is an **organophosphate**, and oximes like pralidoxime are **strongly indicated** for reactivating **acetylcholinesterase** inhibited by organophosphates. - Oximes are a crucial part of recommended antidotal therapy alongside **atropine** for severe organophosphate poisoning. - Must be administered early (within 24-48 hours) before **aging** of the phosphorylated enzyme occurs. *Phorate* - Phorate is a highly toxic **organophosphate pesticide**, and oximes are **indicated** for treatment of phorate poisoning. - Oximes work by **dephosphorylating** (nucleophilic attack on) the acetylcholinesterase enzyme, which has been inhibited by the organophosphate, restoring its catalytic function. *Malathion* - Malathion is an **organophosphate insecticide**, and oxime reactivators are **effective** in malathion poisoning. - The mechanism involves **cleaving the phosphate bond** from the serine residue on the acetylcholinesterase enzyme, allowing it to metabolize acetylcholine again and reverse cholinergic toxicity.

Question 1

Which drug is most commonly associated with causing fixed drug eruptions?

Accepted Answer

Sulfonamide

Answer

Aminoglycoside

Answer

Erythromycin

Answer

None of the options

Question 2

Which drug would be most appropriate for treating a patient with suspected chlamydia-gonorrhea coinfection?

Accepted Answer

Doxycycline

Answer

Ciprofloxacin

Answer

Nalidixic acid

Answer

Norfloxacin

Question 3

Which of the following statements about Selective Estrogen Receptor Modulators (SERMs) is correct?

Accepted Answer

Some SERMs can act as both agonists and antagonists on estrogen receptors.

Answer

Act as agonists on estrogen receptors.

Answer

Used to reduce the risk of hot flushes and thromboembolism.

Answer

Act as antagonists on estrogen receptors.

Question 4

The mechanism by which ergometrine stops postpartum hemorrhage is that it:

Accepted Answer

Increases tone of uterine muscle

Answer

Induces platelet aggregation

Answer

Promotes coagulation

Answer

Causes vasoconstriction of uterine arteries

Question 5

Depot preparations are administered by ?

Accepted Answer

Both subcutaneous and intramuscular route

Answer

Subcutaneous route

Answer

Intravenous route

Answer

Intramuscular route

Question 6

True about MDMA:

Accepted Answer

Ecstasy is another name for it

Answer

It is a cocaine congener

Answer

Methadone is used to treat withdrawal symptoms

Answer

Causes parkinsonism like syndrome

Question 7

Which of the following is used in the second-line management of strychnine poisoning?

Accepted Answer

Barbiturates

Answer

Physostigmine

Answer

Naloxone

Answer

Diazepam

Question 8

Knockout drops are:

Accepted Answer

Chloral hydrate

Answer

Kerosene

Answer

Paraldehyde

Answer

Turpentine

Question 9

Acrodynia, or Pink disease, occurs in poisoning with which of the following substances?

Accepted Answer

Mercury

Answer

Lead

Answer

Thallium

Answer

Arsenic

Question 10

Oximes are contraindicated in which poisoning:

Accepted Answer

Carbamate

Answer

Diazinon

Answer

Phorate

Answer

Malathion

NEET-PG 2013 — Pharmacology