Cannabis Flashcards
Psychoactive effects due to presence of chemicals
termed
cannabinoids
Regulated use suitable for end-of-life care
for symptoms associated with terminal
disease
- Chronic pain
- Anorexia
- Nausea
- Arthritis
- Seizures
Medical use
Multiple sclerosis, spinal cord
injury/disease, cancer, HIV/AIDS, epilepsy
Psychoactive effects - Cannabis contains more than
n 85 psychoactive
cannabinoids, of which two are most prominent.
Cannabis contains more than 85 psychoactive
cannabinoids, of which two are most prominent
THC
Cannabidiol
THC
the principal psychoactive component
and is responsible for euphoric and antiemetic
effects.
Cannabidiol
s 2nd major cannabinoid and is
responsible for relaxation and anxiolytic effects
of cannabis.
Cannabinoids are generally thought to be
defensive chemicals to discourage predation
Cannabinoids are enriched in
specialized
structures on the flowering bodies known as trichomes
Hashish
is produced from
trichomes (kief)
Increased cannabinoid content Hash is a
solid
pressed cake of trichomes (50 - 90% THC)
Hash oil is an
alcohol extract of trichomes
reduced to a viscous liquid
Cannabinoids are typically
administered by
inhalation
(smoking) or orally (e.g. baked
goods)
Inhalation
Rapid entry to bloodstream
Recovery of ~20% of THC content
Oral administration
Slow, prolonged, but variable uptake
* Much less efficient due to breakdown in GI,
slow absorption, and first-pass metabolism
Oral administration results in
n less absorption but prolonged
elevation of THC in blood due to sustained absorption over time.
Cannabinoids are
lipid-soluble and cross
the BBB
Onset of psychoactive effects is delayed by
5-30 minutes (longer for oral
administration)
Rapid uptake into blood paradoxically
does
not lead to rapid uptake into brain
THC is metabolized in the
liver by
cytochrome P450 enzymes
Primary metabolite is
11- OH-THC, psychoactive
Secondary inactive metabolite is
THC-COOH
- Half-life of THC is
very long: 20-30 hours
Slow elimination is exacerbated by
release
from lipid stores
11-OH-THC and THC-COOH are excreted
unmodified in feces
Glucuronic acid esters of THC-COOH
are also excreted in
urine
Due to slow release from lipid stores
THC metabolites can be detected for
weeks after a single dose
Father of Psychopharmacology
Jacque-Joseph Moreau, 18th ce
Psychiatrist
Drug effects - Subjective effects (low to moderate doses)
- Initial light-headedness or dizzyness
- Euphoria and exhilaration
- Calm, relaxed, dreamlike state (‘stoned’)
Physiological effects
- Dilation of small blood vessels in eyes and skin
- Increased heart rate, decreased blood pressure
- Dry mouth – compulsion to drink
- Increased appetite
Adverse effects
- Anxiety or panic associated with feelings of paranoia
- Delirium or hallucinations extremely rare
Can precipitate psychosis in
schizophrenia
Headaches reported with
increased doses
- Intoxication can result in
disordered thinking or
speech and inability to remain focused on a topic
No effects on
recall of information (previously
encoded
THC administration may impact (dose dependent)
explicit memory
encoding/recall (short-term memory)
Previous exposure may decrease
cognitive effects
Deficits seen in tasks requiring
sustained attention
No decrease in simple reaction time measures BUT
impairs ability to drive
Interaction with alcohol
– low dose cannabis use exacerbates the impairment due to alcohol
Impairments may relate to attention deficits
impaired ability to attend to peripheral stimuli
In animals: IV THC admin results in mixed effects on locomotion - Low doses
mixed stimulant and depressant effects
In animals: IV THC admin results in mixed effects on locomotion - high doses
more uniform motor depression – catalepsy (lack of voluntary movement)
Administration results in deficits in various learning and memory tasks
Radial arm maze, Morris water maze,
Impairment seen with direct intrahippocampal injection of
THC
Therapeutic effects
Decreases ocular pressure
Antiemetic
Orexigenic
Anxiolytic
Anticonvulsant and antipsychotic
Anti-spastic
Analgesic
Anti-oxidant and neuroprotective
Decreases ocular pressure
useful adjunctive therapy for treatment of glaucoma
AntiemetiC
promoted as treatment for chemotherapy associated nausea
Orexigenic
treatment for disease associated anorexia (cancer, HIV/AIDS)
Anxiolytic
therapeutic potential for psychiatric illness
Anticonvulsant and antipsychotic
esp. strains high in CBD
Anti-spastic –
– treatment for spinal injury / disease (MS, TBI, SCI)
- Analgesic
modulation of pain response
- Anti-oxidant and neuroprotective
various cannabinoids are antioxidant and neuroprotective
against glutamatergic toxicity
