Hallucinogens — MCQs
Ocular effects that include mydriasis are characteristic of which of the following drugs?
True about MDMA:
A 16-year-old boy suffering from drug abuse presents with a cross-over of sensory perceptions, where sounds can be seen and colors can be heard. Which of the following is the most likely agent responsible for the drug abuse?
Management of a violent patient in psychiatry includes all except:
Treatment of dhatura poisoning is done with:
A mother reports that her daughter ingested a substance in an unknown dose. The girl presents with hypertension, tachycardia, mydriasis, and hyperthermia. What is the most likely substance?
Which of the following drugs produces dissociative anesthesia?
Which of the following is NOT considered a 'date rape drug'?
Which Benzodiazepine decreases post-operative nausea & vomiting:-
Which of the following antidepressants is least likely to have sexual side effects?
Hallucinogens Indian Medical PG Practice Questions and MCQs
Question 1: Ocular effects that include mydriasis are characteristic of which of the following drugs?
- A. phenylephrine (alpha agonist) (Correct Answer)
- B. neostigmine (cholinesterase inhibitor)
- C. phentolamine (alpha blocker)
- D. mecamylamine (ganglionic blocker)
Explanation: ***phenylephrine (alpha agonist)*** - **Phenylephrine** is a direct-acting **alpha-1 adrenergic agonist** that causes contraction of the **pupillary dilator muscle**, leading to **mydriasis** (pupil dilation). [1] - It is frequently used clinically to dilate pupils for **ophthalmologic examinations** due to its selective action on alpha-1 receptors in the eye. [2] *neostigmine (cholinesterase inhibitor)* - **Neostigmine** inhibits acetylcholinesterase, increasing acetylcholine at the neuromuscular junction and muscarinic receptors. This leads to **miosis** (pupil constriction), not mydriasis. - Its ophthalmic use is primarily for treating **glaucoma** by improving aqueous humor outflow through cholinergic effects on the ciliary muscle. *phentolamine (alpha blocker)* - **Phentolamine** is a **non-selective alpha-adrenergic antagonist** that blocks both alpha-1 and alpha-2 receptors. - Alpha-1 receptor blockade in the eye would relax the pupillary dilator muscle, leading to **miosis** or prevention of mydriasis, not its induction. *mecamylamine (ganglionic blocker)* - **Mecamylamine** is a **ganglionic blocker** that antagonizes nicotinic receptors in both sympathetic and parasympathetic ganglia. - Blocking parasympathetic ganglia can cause some mydriasis, but ganglionic blockers have widespread, non-selective autonomic effects and are not primarily used for isolated mydriasis.
Question 2: True about MDMA:
- A. It is a cocaine congener
- B. Methadone is used to treat withdrawal symptoms
- C. Ecstasy is another name for it (Correct Answer)
- D. Causes parkinsonism like syndrome
Explanation: 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.
Question 3: A 16-year-old boy suffering from drug abuse presents with a cross-over of sensory perceptions, where sounds can be seen and colors can be heard. Which of the following is the most likely agent responsible for the drug abuse?
- A. Cocaine, a stimulant that can cause heightened sensory perception and euphoria.
- B. PCP, a dissociative drug that can cause hallucinations and altered sensory perceptions.
- C. Marijuana, a psychoactive substance that can alter perception and cause mild hallucinations.
- D. LSD, a hallucinogen known for causing synesthesia and intense sensory distortions. (Correct Answer)
Explanation: **LSD, a hallucinogen known for causing synesthesia and intense sensory distortions.** - **LSD (lysergic acid diethylamide)** is a classic **psychedelic** known for inducing profound alterations in perception, mood, and thought. - **Synesthesia**, the experience of a crossover of sensory perceptions (e.g., seeing sounds, hearing colors), is a hallmark effect of LSD, directly aligning with the patient's symptoms. *Cocaine, a stimulant that can cause heightened sensory perception and euphoria.* - **Cocaine** primarily acts as a stimulant, leading to increased alertness, euphoria, and sometimes paranoia or tactile hallucinations (e.g., **cocaine bugs**). - It does not typically cause synesthesia or the profound cross-sensory distortions described, which are more characteristic of hallucinogens. *PCP, a dissociative drug that can cause hallucinations and altered sensory perceptions.* - **PCP (phencyclidine)** is a dissociative anesthetic that can cause detachment, hallucinations, and altered perception of reality, often leading to bizarre or aggressive behavior. - While it causes altered sensory perceptions, the specific symptom of cross-sensory experiences like seeing sounds or hearing colors (**synesthesia**) is less characteristic of PCP and more strongly associated with classic hallucinogens. *Marijuana, a psychoactive substance that can alter perception and cause mild hallucinations.* - **Marijuana** (cannabis) can alter perception, enhance sensory experiences, and, at higher doses, produce mild hallucinations or distortions. - However, the intense and distinct cross-sensory phenomenon of synesthesia, where sounds are seen and colors heard, is rarely (if ever) the primary or most pronounced effect of marijuana use.
Question 4: Management of a violent patient in psychiatry includes all except:
- A. CBT (Correct Answer)
- B. Haloperidol
- C. ECT
- D. BZD
Explanation: ***CBT*** - **Cognitive Behavioral Therapy (CBT)** is a long-term psychological intervention aimed at changing maladaptive thought patterns and behaviors. It is **not suitable for immediate management** of an acutely violent patient. - While CBT can be beneficial for aggression management in a stable patient, it requires patient cooperation, cognitive engagement, and time, which are not available during a **violent psychiatric emergency**. *Haloperidol* - **Haloperidol** is a potent typical antipsychotic frequently used in acute settings for rapid tranquilization of violent or severely agitated patients. - It is effective in reducing **psychosis-related agitation** and can be administered **intramuscularly** for quick onset of action. - Often used in combination with benzodiazepines for optimal control of acute violence. *ECT* - **Electroconvulsive Therapy (ECT)** may be considered in **severe, treatment-resistant cases** of violence associated with conditions like uncontrolled mania, catatonic excitement, or psychotic depression when pharmacological interventions have failed. - While not used for immediate acute management due to logistical requirements (consent, anesthesia, specialized setup), it can be an effective option for severe psychiatric conditions with persistent violence. - It works by inducing a brief controlled seizure, which can rapidly alleviate severe symptoms. *BZD* - **Benzodiazepines (BZDs)** like lorazepam or diazepam are **first-line agents** in the acute management of violent or agitated patients due to their rapid anxiolytic, sedative, and muscle relaxant properties. - They are particularly useful for **calming acute agitation** and are often combined with antipsychotics for rapid tranquilization. - Can be administered intramuscularly or intravenously for quick action in psychiatric emergencies.
Question 5: Treatment of dhatura poisoning is done with:
- A. Physostigmine (Correct Answer)
- B. Neostigmine
- C. Naloxone
- D. Pilocarpine
Explanation: ***Physostigmine*** - **Physostigmine** is a **reversible cholinesterase inhibitor** that can cross the **blood-brain barrier**, allowing it to counteract both peripheral and central anticholinergic effects of dhatura poisoning. - It increases the amount of **acetylcholine** at muscarinic and nicotinic receptors, directly competing with the anticholinergic agents. *Neostigmine* - **Neostigmine** is also a **cholinesterase inhibitor**, but it does not cross the **blood-brain barrier** effectively. - Therefore, it is primarily used for its **peripheral effects** and is not suitable for reversing the central nervous system manifestations of dhatura poisoning. *Naloxone* - **Naloxone** is a **pure opioid antagonist** used to reverse the effects of **opioid overdose**. - It has no role in the treatment of **dhatura poisoning**, which involves anticholinergic toxicity. *Pilocarpine* - **Pilocarpine** is a **direct muscarinic agonist** that acts at peripheral muscarinic receptors. - While it could counteract some peripheral anticholinergic effects, it does not cross the **blood-brain barrier** effectively and cannot address the central nervous system manifestations. - It is not the preferred or primary antidote for **anticholinergic toxicity** as it doesn't address both central and peripheral effects like physostigmine does.
Question 6: A mother reports that her daughter ingested a substance in an unknown dose. The girl presents with hypertension, tachycardia, mydriasis, and hyperthermia. What is the most likely substance?
- A. Heroin
- B. Morphine
- C. Cocaine (Correct Answer)
- D. Chlorpheniramine
- E. Organophosphate
Explanation: ***Cocaine*** - The presented symptoms of **hypertension, tachycardia, mydriasis, and hyperthermia** are characteristic of a **sympathomimetic toxidrome**, frequently caused by cocaine overdose. - Cocaine acts as a **norepinephrine-dopamine-serotonin reuptake inhibitor**, leading to excessive stimulation of the central and peripheral nervous systems. *Heroin* - Heroin is an **opioid**, and overdose generally presents with **respiratory depression, bradycardia, miosis (pinpoint pupils)**, and hypotension, which are contrary to the patient's symptoms. - Patients typically exhibit central nervous system **depression**, rather than the hyperactive state seen here. *Morphine* - Similar to heroin, morphine is an **opioid** and causes symptoms like **respiratory depression, bradycardia, miosis**, and hypotension. - These effects are the opposite of the **sympathomimetic** signs observed in the patient. *Chlorpheniramine* - Chlorpheniramine is an **antihistamine** with significant **anticholinergic effects**. An overdose might cause **mydriasis and tachycardia**, but not typically severe hypertension or hyperthermia as the primary features. - Other anticholinergic signs such as **dry mucous membranes, urinary retention, and altered mental status (delirium)** would also be expected. *Organophosphate* - Organophosphate poisoning causes a **cholinergic toxidrome** due to **acetylcholinesterase inhibition**, resulting in excessive cholinergic stimulation. - Classic presentation includes **SLUDGE syndrome** (Salivation, Lacrimation, Urination, Defecation, GI upset, Emesis) along with **miosis (pinpoint pupils), bradycardia, bronchospasm**, and muscle fasciculations. - These findings are the **opposite** of the sympathomimetic signs seen in this patient.
Question 7: Which of the following drugs produces dissociative anesthesia?
- A. Ketamine (Correct Answer)
- B. Propofol
- C. Thiopentone
- D. Enflurane
Explanation: ***Ketamine*** - **Ketamine** is a **dissociative anesthetic** that causes a trance-like state characterized by profound analgesia, amnesia, and catatonia, with the patient appearing to be awake but unresponsive. - It works by antagonizing the **NMDA receptor**, leading to a functional dissociation between the limbic and cortical systems. *Propofol* - **Propofol** is a short-acting intravenous anesthetic that produces a rapid loss of consciousness and has sedative-hypnotic properties. - It functions primarily by enhancing the activity of the **GABA-A receptor**, leading to central nervous system depression, not dissociation. *Thiopentone* - **Thiopentone** (Thiopental) is a barbiturate that induces rapid anesthesia and is used for induction and short procedures. - Its mechanism involves potentiation of the **GABA-A receptor**, causing global central nervous system depression without dissociative effects. *Enflurane* - **Enflurane** is an inhaled halogenated ether anesthetic that provides excellent muscle relaxation and analgesia. - It primarily acts by enhancing **GABAergic inhibition** and inhibiting excitatory neurotransmission, producing general anesthesia rather than a dissociative state.
Question 8: Which of the following is NOT considered a 'date rape drug'?
- A. Rohypnol
- B. Ketamine
- C. Gamma hydroxyl butyrate
- D. Propofol (Correct Answer)
Explanation: ***Propofol*** - **Propofol** is an **intravenous anesthetic** and sedative primarily used in medical settings for induction and maintenance of anesthesia or for sedation in critical care. - While it can cause sedation and amnesia, it is not commonly associated with or used as a **'date rape drug'** due to its rapid onset and short duration of action, requiring medical administration. *Rohypnol* - **Rohypnol** (flunitrazepam) is a potent **benzodiazepine** known for its sedative-hypnotic effects and is commonly explicitly referred to as a **'date rape drug'**. - It can cause **amnesia**, muscle relaxation, and impaired judgment, making victims vulnerable and unable to recall events. *Ketamine* - **Ketamine** is a **dissociative anesthetic** that causes a trance-like state, pain relief, sedation, and amnesia, and is also known as a **'date rape drug'**. - At lower doses, it can produce **hallucinations** and a sense of detachment, impairing a person's ability to resist or remember. *Gamma hydroxyl butyrate* - **Gamma-hydroxybutyrate (GHB)** is a **central nervous system depressant** that has been widely implicated as a **'date rape drug'**. - It rapidly induces **sedation**, euphoria, and amnesia, with effects often lasting for several hours.
Question 9: Which Benzodiazepine decreases post-operative nausea & vomiting:-
- A. Midazolam (Correct Answer)
- B. Diazepam
- C. Lorazepam
- D. All of the options
Explanation: ***Midazolam*** - **Midazolam** is a commonly used benzodiazepine in anesthesia that has been shown to have **antiemetic properties** and can decrease the incidence of **postoperative nausea and vomiting (PONV)**. - Its mechanism may involve its sedative and anxiolytic effects, indirectly reducing the triggers for nausea. *Diazepam* - While **diazepam** is a benzodiazepine with sedative and anxiolytic effects, it is not primarily known for reducing PONV. - Its longer duration of action compared to midazolam can also contribute to unwanted **postoperative sedation**. *Lorazepam* - **Lorazepam** is another benzodiazepine used for anxiolysis and sedation but is not a primary agent for the prevention of PONV. - Like diazepam, its prolonged effects can lead to **delayed recovery** and drowsiness, which may not be desirable in the postoperative period. *All of the options* - While all listed drugs are benzodiazepines, only **midazolam** is consistently recognized and utilized for its ability to reduce PONV in the perioperative setting. - The other benzodiazepines do not demonstrate the same consistent benefit in PONV reduction and may have other side effects that limit their utility for this specific purpose.
Question 10: Which of the following antidepressants is least likely to have sexual side effects?
- A. Amitriptyline
- B. Fluoxetine
- C. Venlafaxine
- D. Mirtazapine (Correct Answer)
Explanation: ***Mirtazapine*** - **Mirtazapine** is an atypical antidepressant (NaSSA - Noradrenergic and Specific Serotonergic Antidepressant) that works by blocking alpha-2 adrenergic receptors, enhancing serotonin and norepinephrine release [1]. - It has the **lowest incidence of sexual side effects** among antidepressants because it blocks 5-HT2 and 5-HT3 receptors while avoiding significant 5-HT1A stimulation, which is responsible for sexual dysfunction with SSRIs [1]. - It may even **improve libido** in some cases due to its unique receptor profile and histamine antagonism that can enhance sleep quality. *Amitriptyline* - **Amitriptyline** is a tricyclic antidepressant (TCA) with broad receptor actions, including anticholinergic and antihistaminic effects. - TCAs like amitriptyline can cause **sexual dysfunction** (including erectile dysfunction and decreased libido) due to their anticholinergic properties and effects on multiple neurotransmitter systems, though typically less severe than SSRIs. *Fluoxetine* - **Fluoxetine** is a selective serotonin reuptake inhibitor (SSRI), and while effective for depression, it is associated with a **high incidence of sexual side effects** (30-70% of patients) [2]. - These side effects include **decreased libido**, **anorgasmia**, and **erectile dysfunction**, caused by increased serotonergic activity at 5-HT2 receptors in areas regulating sexual function [2]. *Venlafaxine* - **Venlafaxine** is a serotonin-norepinephrine reuptake inhibitor (SNRI), increasing both serotonin and norepinephrine levels in the brain [1]. - Like SSRIs, SNRIs such as venlafaxine frequently cause **sexual dysfunction**, with common complaints including reduced libido and difficulty achieving orgasm due to enhanced serotonergic neurotransmission [1].
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