NEET-PG 2013 - Pharmacology Practice Questions

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: 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.

Q: Angel dust is:

Phencyclidine. ***Correct: Phencyclidine*** - **Phencyclidine (PCP)** is commonly known by the street name **"angel dust"** - It is a **dissociative anesthetic** with hallucinogenic and neurotoxic effects - Acts primarily as an **NMDA receptor antagonist** *Incorrect: LSD* - **LSD (lysergic acid diethylamide)** is a classic hallucinogen with the street name "acid," not angel dust - It primarily affects **serotonin receptors (5-HT2A)** and causes profound alterations in perception and thought - Chemically and pharmacologically distinct from PCP *Incorrect: Cannabis* - **Cannabis** is a psychoactive drug derived from the *Cannabis* plant, commonly known as marijuana or weed - Its active compound **THC (tetrahydrocannabinol)** produces euphoric and relaxing effects through cannabinoid receptors - Not related to the street name "angel dust" *Incorrect: Morphine* - **Morphine** is a potent **opioid analgesic** used for pain relief - Acts as a **CNS depressant** through mu-opioid receptors - Unlike PCP's dissociative and stimulant effects, morphine produces sedation and analgesia

Q: Which is not used in status epilepticus?

Metformin. ***Metformin*** - **Metformin** is an **oral hypoglycemic agent** used to treat **type 2 diabetes mellitus** and has no role in the management of seizures or status epilepticus. - Its primary mechanism involves decreasing **hepatic glucose production** and improving **insulin sensitivity**. *Lorazepam* - **Lorazepam** is a first-line treatment for **status epilepticus** due to its rapid onset of action and efficacy in terminating seizures. - It enhances the effect of **GABA** (gamma-aminobutyric acid) at the GABA-A receptor, leading to neuronal hyperpolarization and reduced excitability. *Phenytoin* - **Phenytoin** is a common second-line agent used in status epilepticus, administered after benzodiazepines, to maintain seizure control. - It works by blocking **voltage-gated sodium channels**, thereby stabilizing neuronal membranes and preventing repetitive firing. *Phenobarbitone* - **Phenobarbitone** (phenobarbital) is an effective antiepileptic drug, often considered as a second or third-line agent in status epilepticus, especially when other treatments fail. - It acts primarily by enhancing the activity of **GABA** at the GABA-A receptor, similar to benzodiazepines, but with a longer duration of action.

Question 1

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 2

Oximes are contraindicated in which poisoning:

Accepted Answer

Carbamate

Answer

Diazinon

Answer

Phorate

Answer

Malathion

Question 3

Angel dust is:

Accepted Answer

Phencyclidine

Answer

LSD

Answer

Cannabis

Answer

Morphine

Question 4

Which is not used in status epilepticus?

Accepted Answer

Metformin

Answer

Lorazepam

Answer

Phenytoin

Answer

Phenobarbitone

NEET-PG 2013 — Pharmacology