Hallucinogens Flashcards
What are the classes of hallucinogens?
Indolealkylamines - similar structure to 5-HT (e.g. LSD)
Phenylethylamines - similar structure to DA (e.g. MDMA)
What is LSD? What is it’s brief history?
Completely synthetic drug taken via blotter paper of liquid (PO administration)
Synthesized in 1938, ingested in 1943
Albert Hoffman discovered it - took at 2.5 mile bike ride on LSD
Classified as schedule 1 in the 60s
What are the effects of LSD?
Onset - .5-1hour - intensification of visual patterns, seeing shapes with eyes closed
Plateau - 1-3hr - more intense visual changes, slowing of time
Peak - 3-6hr - suspension of time, synaesthesia
Come down - 6-18hrs
What is the dose to see detectable symptoms
20mg
What are the adverse effects of LSD?
Psychosis, flashbacks, HPPD
What is psilocybe (magic mushrooms)?
Similar effects to LSD but shorter (4-7hrs)
Active ingredient = psilocybin
Are there any problems associated with long term use of LSD/psilocybe?
Little evidence for long last mental health problems
Little evidence for addiction as no withdrawal symptoms and animals don’t self-admin
Positive persistent effects seen when patients report meaningful life experiences
What is mescaline?
Found in peyote cactus in the dried flowers
Similar effects to LSD
What is MDMA? What’s its brief history?
Synthetic drug which resembles amphetamines
Synthesised in 1912, used in psychotherapy until became illegal in 1977
What are the effects of MDMA?
Onset - .5-1.5hrs
Lasting effects - 5-6hours
Sense of wakefulness, endurance, euphoria, well-being
Urge to communicate and feel close with others
What are the undesirable effects of MDMA?
Can cause anxiety, distortion of ideas
Frequent use results in undesirable side effects
How is serotonin synthesized?
L-Tryptophan -> L-5-Hydroxytyptophan (5-HTP) -> 5-Hydroxytryptamine (5-HT)
L-Tryp -> 5-HTP = tryptophan hydroxylase (rate-limiting step)
5-HTP -> 5-HT = aromatic L-amino acid decarboxylase
What are the two kinds of 5-HTRs?
5-HT1A = inhibitory as reduces cAMP by inhibiting adenyl cyclase
5-HT2A = excitatory as increases PKC
How do hallucinogens work?
Complex interactions with receptors
Think LSD acts as 5-HT agonist on 5-HT1A receptor in raphe nuclei
-inhibits firing of raphe nuclei but cannot cause hallucinogenic effects
What is the proposed mechanism of action for hallucinogens?
PFC overload - activation of later V pyramidal neurons via increase glutamate of 5-HT2A stimulation
