Lysergic acid diethylamide (LSD)

(Redirected from LSD)


  • Also known as d-lysergic acid diethylamide


Serotonin-like agents, like LSD, have similar chemical properties of serotonin. These are 5-HT2 agonists, mediating excitatory neurotransmitter release.[1] LSD also binds to dopaminergic receptors, contributing to its psychogenic affects.[2]


  • Known as one of the most potent psychoactive drug, doses of minimum of 25μg. Doses of 1 to 1.5 μg/kg produce psychedelic effects, with the “optimum” dosage for a typical fully unfolded LSD reaction is estimated to be in the range of 100–200 μg.
  • Route of administration can be PO (most common), IM, or IV.[3]
    • PO: Usual Dose 100-250μg, Onset 30-45mins, Peak effect 1-2.5hrs, Total duration 9-12hrs
    • IM: Usual Dose 100-250μg, Onset 15-20mins, Peak effect 1hr, Total duration 9-10hrs
    • IV: Usual Dose 40-180μg, Onset 3-5mins, Peak effect 1hr, Total duration 9-10hrs
  • Tolerance to LSD-25 builds up over consistent use and cross-tolerance has been demonstrated between LSD, mescaline and psilocybin.[4]

Clinical Features

The acute ingestion of LSD is described as: "The initial effects begin 20-40 minutes with a sense of euphoria and dizziness...LSD is best described as a drug that strikes down barriers. The person who uses LSD is likely to feel detached from his/her ego, and can cross between states of consciousness. The user's perceptions are altered, causing visual and auditory hallucinations. One may notice that the walls of room are "breathing" or that motionless curtains appear to be moving. Senses appear to mix: a user might see music, taste colors, or hear visual stimuli. The LSD experience is often difficult to describe by users -- words lose meaning and are often insufficient in describing the effects of the drug; thoughts may seem unclear. Effects taper off after about 6-8 hours and are usually completely gone after a nights sleep."[5]

"Good Trips" are much like what is described as above, with seemingly normal or usual objects and experiences appearing new and changed to something breath-taking.

"Bad Trips" include experiences of paranoia, acute panic reactions, and agitation, usually stemming from the users prior mood to ingesting LSD. This, along with the user's altered perception of their environment, can lead to the user being subjected to dangers resulting in serious injury, disability, or death.

Differential Diagnosis

Serotonin-Like Agents

  • LSD
  • Psilocybin and psilocin dimethyltryptamine (DMT) and 5-methoxy- dimethyltryptamine (5-MeO-DMT)
  • Naturally occurring plants like :Hawaiian baby woodrose (Argyreia nervosa), Hawaiian woodrose (Merremia tuberosa), morning glory (Ipomoea violacea), and olili- uqui (Rivea corymbosa)


Dissociative Agents

Plant-based Hallucinogenics

  • Marijuana
  • Salvia
  • Absinthe
  • Isoxazole Mushrooms

Psychiatric Illnesses


  • Usually clinical, based on history and presentation

Most blood and urine tests are restricted to research and unavailable for clinical usage

Research Tests

  • Found in blood specimens (6–12 hours) and urine (2–4 days) after usage
  • Metabolite (2-oxo-3-hydroxy-LSD) present in urine for a longer time than LSD itself.[6]


  • Assess for signs of trauma or exposure
  • Assure patient and staff safety
  • Agitation:
    • Ativan 1-2mg IV, titrate to effect
    • Haloperidol 5-10mg IV, titrate to effect (use as 2nd line agent as may lower seizure threshold)

Consider co-ingestions, hypoglycemia, and risk for rhabdomyolysis[7]


  • Simple LSD ingestion can be safely discharged after a period of observation, once patient has returned to sober baseline and has a safe disposition plan (~4-6 hours)
  • Symptoms lasting longer than 8-12hrs can be managed in an observation unit or admitted

See Also

External Links


  1. Ly, B. "Hallucinogens", Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th Ed. Pgs 2010-2012
  2. Marona-Lewicka D, Thisted RA, Nichols DE (2005). "Distinct temporal phases in the behavioral pharmacology of LSD: Dopamine D2 receptor-mediated effects in the rat and implications for psychosis". Psychopharmacology 180 (3): 427–435.
  3. Passie, T. "The Pharmacology of Lysergic Acid Diethylamide: A Review". CNS Neuroscience & Therapeutics, Volume 14, Issue 4, pages 295–314, Winter 2008
  4. Passie, T. "The Pharmacology of Lysergic Acid Diethylamide: A Review". CNS Neuroscience & Therapeutics, Volume 14, Issue 4, pages 295–314, Winter 2008
  6. Passie, T. "The Pharmacology of Lysergic Acid Diethylamide: A Review". CNS Neuroscience & Therapeutics, Volume 14, Issue 4, pages 295–314, Winter 2008
  7. Glaspy, J. "Drugs of Abuse". Emergency Medicine Manual, 6th Ed. Chapt 103, Pgs 502-504.