Hallucinogens, Phencyclidine, Ketamine Flashcards
What are the five indoles hallucinogens?
- LSD lysergic and diethylamide
- psilocybin and psilocin
- bufotenin
- ibogaine
- dimethyltryptamine (DMT)
What are the phenylethylamine hallucinogenics that also produce amphetamine-like stimulants?
mescaline
methylenediooxymethamphetamine (MDMA)
What is the typical dose of LSD?
25-500mcg
How long for LSD effects and what is involved?
initial effects 30mins-2 hours
somatic and autonomic involvement
What are the sympathomimetic effects?
pupillary dilation, increase in blood pressure, tachycardia, piloerection, hyperflexia, tremors, increase in body temperature
What are the somatic effects?
dizziness, weakness, paresthesias, nausea
What are the subjective psychic changes?
anxiety, euphoria, giddiness, emotional lability, early stage is perceived as pleasant
When do the hallucinogenic effects develop in LSD?
Slowly in 1-3 hours.
What characterizes the hallucinogenic phase of LSD?
sensory distortions, depersonalization, difficulty differentiating drug effects from reality, anxiety, fear, paranoia, panic, emotional lability
What are the signs of acute poisoning with LSD?
Death from overdose is rare with LSD. More common in phenylethlamines.
panic reactions, fear, paranoia.
Treatment involves calming and reassuring patient. Anxiolytics.
These hallucinogenics are found in mushrooms and are similar to LSD?
psilocin psilocybin
This is similar to LSD but is much shorter.
Dimethyltryptamine ~1hour
This is found in mushrooms and the skin of amphibians.
Bufotenin
This is found in buttons of the peyote cactus, the somatic autonomic changes are more pronounced.
Mescaline
This is both a hallucinogenic and stimulant.
MDMA
This is an alkaloid found in the roots of an African shrub. It can suppress the craving for heroin cocaine.
Ibogaine
When does tolerance occur in LSD?
Very rapidly after 2-3 doses.
Cross tolerance amoung hallucinogens
Do not cause physical dependence (phenylethlamines exception)
Psychologic dependence occurs
What is an unusual aspect of the use of hallucinogens?
Flashback phenomenon. Long-term alterations in neuronal functions. Memories are triggered by a variety of cues.
Heavy LSD use that is associated with long-term changes in visual information processing is called?
HPPD
hallucinogen persisting perception disorder
What is the proposed mechanism of action of hallucinogens?
Agonists at 5-HT2 presynaptic receptors
Decrease firing in the dorsal raphe nucleus
Alter reticular sensory filtering system.
May effect dopamine, enkephalins
This drug is often mixed with marijuana. It is slowly eliminated, rapidly absorbed.
Phencyclidine
How do the different doses of phencyclidine cause different effects?
Low dose - marijuana
High dose - amphetamine-like stimulant (restlessness, irritable, hostile)
Highest dose - psychotic, rage, hallucinations
What reactions are more common with phencyclidine than other drugs?
psychotic
What are common among heavy users?
social withdrawal, isolation, cognitive disturbances
What can phencyclidine cause?
hyperflexia, increase muscle strength, analgesic activity.
What is the mechanism of action of phencyclidine?
blockade of NMDA receptors
What are the symptoms of acute poisoning of phencyclidine?
Hyperreflexia, increased muscle tone, hypertension, vertical nystagmus, hostile, agression, hallucinations, convulsions,
How do you treat acute poisoning of phencyclidine?
Support respiration.
Antipsychotics, benzodiazepines, anticonvulsant, antihypertensive, acidify urine
What are the symptoms of withdrawal, do they require treatment?
craving for drug, fear, anxiety, restlessness.
No treatment required.
What are the hazards associated with long term use of phencyclidine?
psychosis and cognitive impairment may persist even after drug is stopped.
