Hallucinogen

Aka: Hallucinogen, Lysergic Acid Diethylamide, Lysergic Acid, LSD, Mescaline, Psilocybin, Psychedelic, Psychotomimetic

1. See Also
   1. Chemical Dependency
   2. Substance Abuse Evaluation
   3. Methoxetamine
   4. Ketamine Abuse
   5. NBOMe (N-Benzylated Phenylethylamine, N-Bomb)
   6. Phencyclidine (PCP)
   7. Synthetic Marijuana
   8. Synthetic Cathinone (Bath Salts)
   9. Chemical Dependency
   10. Substance Abuse Evaluation
   11. Agitated Delirium
   12. Unknown Ingestion
2. Types: Hallucinogens
   1. Psychedelic Agents (Classic Hallucinogens)
      1. Lysergic Acid Diethylamide (LSD)
         1. Street Names: Acid, Sugar, Cubes, Trips, Windowpane, Blotter
      2. Mescaline
         1. Street Names: Buttons, beans, Cactus
      3. Psilocybin
         1. Street Names: Magic Mushrooms, Mushrooms, Los Ninos
   2. Dissociative Agents
      1. Ketamine
      2. Phencyclidine (PCP)
   3. Delirium-Inducing Agents
      1. See Medication Causes of Delirium in the Elderly
      2. See Medication Causes of Psychosis
      3. Anticholinergic Toxicity (e.g. Diphenhydramine)
3. Background: Classic Hallucinogens (Psychedelics)
   1. Derivations
      1. LSD semisynthetically derived from ergot alkaloids
      2. Mescaline naturally derived from peyote
      3. Psilocybin naturally derived from Psilocybe
   2. Pharmacokinetics
      1. LSD (50-400 ug): 8-12 hour duration
      2. Mescaline (250-600 mg): 8-12 hour duration
      3. Psilocybin (10-50 mg): 6-8 hour duration
   3. Mechanism
      1. Classic Hallucinogens (Psychedelic agents) act at 5-HT2A receptors
      2. Decreases brain blood flow to the default mode network, that in part differentiates self from non-self
         1. Results in dissociation effects of Hallucinogens
4. Signs
   1. See Intentional Drug Overdose
   2. Varies widely based on substance used (which is often unknown)
      1. Polysubstance ingestion is common
      2. Adulterated drugs, variable street names and unique designer drugs are common
   3. Hyper-suggestible state
5. Complications: Toxicity
   1. Serotonin Syndrome
      1. Lysergic Acid Diethylamide (LSD) has high affinity for Serotonin receptors
      2. NBOMe has even higher Serotonin receptor affinity than LSD
   2. Amphetamine-like reaction
      1. Hyperthermia
      2. Rhabdomyolysis
      3. Cerebral Infarction
   3. Water Intoxication with severe Hyponatremia
      1. See Hyponatremia Management
      2. Most common with MDMA (Ecstasy)
      3. Observe for Seizures
6. Management: Hallucinogen Intoxication
   1. See Calming the Agitated Patient
   2. Benzodiazepines (e.g. Midazolam, Lorazepam) are first-line agents
   3. Avoid Neuroleptics (e.g. Haloperidol) in most cases
      1. Risk of Drug Interaction with Hallucinogens used (esp. Anticholinergic Agents)
   4. Provide calm and supportive environment
      1. Isolated room with minimal stimuli and dim lighting
   5. Disposition
      1. Stable patients may be discharged after 1-2 hours of observation with a sober adult
      2. Persistent Psychedelic effects warrant longer observation (higher risk of death related to Traumatic Injury)
7. References
   1. McCollum (2020) EMRap 20(4):9-10