Hallucinogens from plants MCQs With Answer

Plant-derived hallucinogens are an important topic for B.Pharm students, covering compounds such as psilocybin, mescaline, DMT, ibogaine, salvinorin A and tropane alkaloids. This introduction explores pharmacology, mechanism of action (notably 5-HT2A and kappa-opioid receptors), metabolism, toxicology, analytical detection, therapeutic research and safety/regulatory considerations. Familiarity with clinical effects, adverse reactions (anticholinergic delirium, cardiovascular risks), extraction risks, and forensic detection methods is essential for pharmacists involved in research, toxicology or patient counseling. These MCQs emphasize receptor pharmacodynamics, metabolic pathways, lab techniques, legal status and clinical implications to deepen understanding and prepare you for applied pharmaceutical practice. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which receptor is primarily implicated in the psychedelic effects of classical serotonergic hallucinogens such as psilocybin and mescaline?

• 5-HT2A receptor
• NMDA receptor
• GABA-A receptor
• Dopamine D2 receptor

Correct Answer: 5-HT2A receptor

Q2. Psilocybin is a prodrug converted in vivo to which active compound responsible for central effects?

• Psilocin
• DMT
• Bufotenin
• Mescaline

Correct Answer: Psilocin

Q3. Mescaline is a naturally occurring phenethylamine primarily found in which plant used in traditional rituals?

• Lophophora williamsii (peyote)
• Amanita muscaria
• Salvia divinorum
• Tabernanthe iboga

Correct Answer: Lophophora williamsii (peyote)

Q4. In ayahuasca preparations, DMT is orally active when combined with MAO-inhibiting beta‑carbolines from which plant?

• Banisteriopsis caapi
• Peyote cactus
• Salvia divinorum
• Psilocybe mushrooms

Correct Answer: Banisteriopsis caapi

Q5. Salvinorin A is pharmacologically distinct because it primarily targets which receptor system?

• Kappa-opioid receptor
• 5-HT2A receptor
• NMDA receptor
• GABA-B receptor

Correct Answer: Kappa-opioid receptor

Q6. Ibogaine’s reported anti-addictive effects involve multiple targets. Which choice best describes its pharmacology?

• NMDA antagonism, kappa-opioid effects and monoaminergic modulation
• Pure mu-opioid agonism only
• Exclusive 5-HT2A agonism
• Only peripheral adrenergic blockade

Correct Answer: NMDA antagonism, kappa-opioid effects and monoaminergic modulation

Q7. Which tropane alkaloid found in Datura and Atropa is well known for producing prominent delirium and amnestic effects?

• Scopolamine
• Psilocin
• Mescaline
• Salvinorin A

Correct Answer: Scopolamine

Q8. For sensitive quantification of psilocin in plasma during pharmacokinetic studies, which analytical technique is most appropriate?

• HPLC-MS/MS
• UV-visible spectrophotometry
• Thin-layer chromatography
• Paper chromatography

Correct Answer: HPLC-MS/MS

Q9. Classical ergotism (from Claviceps species) historically produced which combination of clinical features?

• Peripheral gangrene and hallucinations
• Renal failure and euphoria
• Bradycardia and seizures
• Hyperglycemia and miosis

Correct Answer: Peripheral gangrene and hallucinations

Q10. Which enzyme rapidly degrades DMT when taken orally without concurrent MAO inhibition?

• Monoamine oxidase (MAO)
• CYP2D6
• COMT
• Acetylcholinesterase

Correct Answer: Monoamine oxidase (MAO)

Q11. Nutmeg-induced hallucinations are attributed primarily to which psychoactive constituent?

• Myristicin
• Psilocin
• Mescaline
• Salvinorin A

Correct Answer: Myristicin

Q12. Which cardiovascular effects are commonly observed with mescaline and psilocybin intoxication?

• Hypertension and tachycardia
• Bradycardia and hypotension
• Severe bradyarrhythmia only
• Profound peripheral vasodilation without tachycardia

Correct Answer: Hypertension and tachycardia

Q13. What is the recommended pharmacological antidote for severe anticholinergic (tropane alkaloid) poisoning?

• Physostigmine
• Naloxone
• Flumazenil
• Activated charcoal

Correct Answer: Physostigmine

Q14. In many jurisdictions psilocybin is classified under which regulatory scheduling category?

• Schedule I / equivalent (no accepted medical use and high abuse potential)
• Over-the-counter (OTC)
• Prescription-only but not controlled
• Unscheduled and legal

Correct Answer: Schedule I / equivalent (no accepted medical use and high abuse potential)

Q15. Tolerance to repeated use of classical psychedelics is largely due to which mechanism?

• 5-HT2A receptor downregulation/desensitization
• Increased MAO enzyme expression
• Upregulation of GABA receptors
• Enhanced renal excretion

Correct Answer: 5-HT2A receptor downregulation/desensitization

Q16. Which cactus species is the primary traditional source of mescaline?

• Lophophora williamsii (peyote)
• Salvia divinorum
• Tabernanthe iboga
• Psilocybe mexicana

Correct Answer: Lophophora williamsii (peyote)

Q17. A major safety concern in clinical use of ibogaine is which cardiac complication?

• QT interval prolongation leading to arrhythmias
• Acute myocardial infarction due to plaque rupture
• Immediate hypertensive crisis
• Pulmonary embolism

Correct Answer: QT interval prolongation leading to arrhythmias

Q18. For reliable botanical identification of psychoactive plant material in the lab, which approach is recommended?

• Combined macroscopic and microscopic examination with voucher specimens
• Solely relying on odor and taste
• Simple pH strip testing
• Refractometry measurements

Correct Answer: Combined macroscopic and microscopic examination with voucher specimens

Q19. Bufotenin, a natural tryptamine, is structurally related to which endogenous neurotransmitter?

• Serotonin
• Dopamine
• GABA
• Acetylcholine

Correct Answer: Serotonin

Q20. Which statement best describes salvinorin A’s pharmacokinetic/pharmacodynamic profile?

• Highly lipophilic with rapid onset and short duration after inhalation
• Orally active with long-lasting effects when swallowed
• Water-soluble with very slow onset
• Exclusively metabolized by CYP3A4 producing prolonged effects

Correct Answer: Highly lipophilic with rapid onset and short duration after inhalation

Q21. Hallucinogen persisting perception disorder (HPPD) is characterized by which clinical feature?

• Recurrent perceptual disturbances or “flashbacks” long after drug use
• Immediate respiratory depression after use
• Permanent paralysis of extremities
• Inability to form new long-term memories

Correct Answer: Recurrent perceptual disturbances or “flashbacks” long after drug use

Q22. Classical serotonergic hallucinogens produce major perceptual changes primarily through agonism at which receptor subtype?

• 5-HT2A receptor
• NMDA receptor
• Kappa-opioid receptor
• Mu-opioid receptor

Correct Answer: 5-HT2A receptor

Q23. Which plant species is commonly implicated in criminal use of scopolamine to induce amnesia or compliance?

• Datura stramonium (jimsonweed)
• Lophophora williamsii
• Psilocybe cubensis
• Banisteriopsis caapi

Correct Answer: Datura stramonium (jimsonweed)

Q24. Harmine, a reversible MAOI present in Banisteriopsis caapi, belongs to which chemical class?

• Beta-carbolines
• Phenethylamines
• Indolealkylamines
• Tropane alkaloids

Correct Answer: Beta-carbolines

Q25. For forensic detection of recent ayahuasca ingestion, which biological sample and time window is most practical?

• Urine within 24–48 hours
• Hair within a few hours
• Saliva after several weeks
• Sweat months later

Correct Answer: Urine within 24–48 hours

Q26. Which clinical finding helps differentiate tropane alkaloid intoxication from classic serotonergic psychedelic intoxication?

• Anticholinergic signs: dry mouth, mydriasis, hyperthermia
• Enhanced social empathy and connectedness
• Prominent geometric visual patterns without autonomic dysfunction
• Mystical-type experiences with preserved orientation

Correct Answer: Anticholinergic signs: dry mouth, mydriasis, hyperthermia

Q27. In preclinical models, which antagonist blocks psilocybin- or LSD-induced head-twitch response, implicating the target receptor?

• 5-HT2A antagonist (e.g., ketanserin)
• NMDA antagonist (e.g., ketamine)
• GABA-A agonist (e.g., muscimol)
• Dopamine D2 antagonist (e.g., haloperidol)

Correct Answer: 5-HT2A antagonist (e.g., ketanserin)

Q28. Which conjugation pathway is primarily responsible for inactivating psilocin during hepatic metabolism?

• Glucuronidation
• Deamination by MAO
• Methylation by COMT
• Sulfation exclusively

Correct Answer: Glucuronidation

Q29. Psilocybin is currently under clinical investigation as a potential treatment for which condition?

• Treatment-resistant depression
• Type 2 diabetes
• Bacterial pneumonia
• Essential hypertension

Correct Answer: Treatment-resistant depression

Q30. When planning a B.Pharm laboratory practical involving plant hallucinogen extraction studies, the critical first safety step is:

• Obtaining appropriate legal/regulatory approvals and controlled-substance handling protocols
• Tasting small extracts to confirm identity
• Disposing extracts down the sink without control
• Working without personal protective equipment to feel the plant texture

Correct Answer: Obtaining appropriate legal/regulatory approvals and controlled-substance handling protocols

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