Cannabis Flashcards
what is a cannabinoid?
- some chemical agents in cannabis
- 60-80
- ex. THC and CBD
cannabis is grown in a hot & dry climate?
- fibre content is weak
- resin is produced making the plant look like it’s covered in dew
cannabis is grown in a cooler more humid environment?
- fibre content increases
- resin content decreases
What was the earliest reported use of cannabis and what was it used for?
- 10,000 yrs ago
- used for fibre properties instead of a psychoactive drug
what is the oldest cultivated plant NOT used for food?
cannabis
Chinese emperor Shen Nung
- used for its psychoactive properties around 2800
When was cannabis introduced to Canada and the US? Who introduced it? What was its use?
- Canada: 1606, by the British
- US: 1611, by the Royal order
- entirely HEMP use
Europe and the mid-1800s
- cannabis was consumed mainly in the form of hashish that was consumed orally
- romantic rage in Europe
Dawamesc
- “sweetmeat”: flower tops, boiled in butter, strained seasoned with vanilla, cinnamon and pistachio
- hash eaters
Cannabis and the late-1800s in North America
- used in medicines
Tea rooms
- cannabis consumption occured in these rooms
- with prohibition in the US, cannabis consumption increased
Harry Anslinger
- waged against all drug use
- cannabis mainly got attention from the law enforcement in the 20s and 30s bc of him
why were cannabis laws justified and what impact did it have?
- cannabis laws were justified bc they thought that minority groups such as African Americans and Mexicans were the primiary users
- this created a negative connotation around the drug
how was cannabis classified in Canada - was this right?
- cannabis was classified as a narcotic
- not right bc only opiates are narcotics but they tried to have a guilt by association
What year was the first legislation made against cannabis
1929
What do recent surverys indicate about canabis use? (3)
- 45% of Canadians aged 15+ have tried cannabis in their life time
- 12% of Canadians aged 15+ have used a cannabis product within the past year
- 33% of these idenify as dailiy users
what is the main psychoactive ingredient in cannabis?
- delta-9-tetrahydrocannabinol
what was the year that THC was isolated and synthesized?
1964
what is the most common cannabis product and was comprises it?
- marijuana
- mixture of dried leaves and flower buds
1970s marijuana vs. today’s marijuana THC content
- 1970s: contained 30mg (2%) THC by weight
- today: contained 60 mg (4%) THC by weight
- marijuana today has doubled in THC content compared to the 70s
Trichome and what does it create
- creates hashish
- cannabinoid-rich glandular hairs which are separated from the plant material
keif and what does it create
- kief is are separated trichomes
- squeezed togetehr to create the block of hashish
What is the general THC content of Hashish?
- varies but genrally 10% THC
how is hash oil prepared and what is the genral THC content
- prepared by boilining cannabis material in a solvent which extracts the cannabinoids
- generally 40% THC
what is the most typical method of administering THC? and how much THC is generally absorbed in that method?
- smoking in the form of a joint (10mg)
- dabbing is also a method
- genrally only 50% of THC in that joint is available for absorption but less than 100% of this is actually absorbed
does THC increase with repeated use?
- there is no extra eperimental evidence to support the effects of marijuana increasing with repeated use
- the individual functionally becomes better at getting more THC when they smoke so they are just getting a larger dose
what is the most effective method for getting marijuana into the brain? when does the onset period occur? when does the peak blood concentration occur? when does the peak effects occur and how long does it last?
- smoking
- onset effects happen in seconds
- peak blood concentrations occur within 10 minutes
- peak effects occur in 30-60minutes and last for 2-4 hours
how do edibles hold up to smoking - when is the onset period, when does the peak blood concentration occur and how long do effects last?
- cannabinoids are slowly and poorly absorbed from the digestive tract
- equivalent effects are produced by an oral dose of THC that is 3x that of an inhaled dose
- peak effects occur 1-3 hours and effects can last up to 5 hours
are cannabinoids lipid-soluble and can cross the blood-brain barrier?
yes
what is the elimination half-life THC?
around 5 days
what are some effects that THC can produce? what are some of the rare effects?
- mild, euphoria, peacefulness, drowsiness, perceptual and time distortions
- rare: hallucinations, delusions and distortions of body image (not sought after effects)
Marijuana as an aphrodisiac
- THC can cause a brief rise in testosterone which may result in an increase in libido
- higher doses and with continued use can cause testosterone levels to drop, reducing libido and producing acute impotency
what are some of the common physiological effects of using marijuana?
- droopy eyelids
- dry mouth
- thirst
- hunger (overeating)
Metrik et. al. study
- they used a balanced placebo design where they found that the large main effects of expectancy on ratings of potency, taste, smell and satisfaction and on observed smoking behaviours
- some effects of marijuana may reflect the placebo effects on people’s expectations
What is the generic and trade name for sesame oil suspension?
- Generic: dronabinol
- Trade: Marinol
What is the generic and trade name for synthetic THC?
- Generic: nabilone
- Trade: Cesamet
What is Sativex?
- oral THC spray that is used for people with MS and other medical conditions
THC as an antiemetic (reduces vomitting)
- given as an adjunct to chemotherapy and for AIDS patients with a loss of appetite
What are better antiemetic than smoking marijuana?
Marinol and Cesamet
what is the most commonly cited useful medical effects of smoked marijuana?
- pain relief
marijuana and pain relief? Smoked vs. Oral THC
- clear evidence to show the link between these 2
- research shows that while the magnitude of peak change in pain sensitivity and tolerance didnt change between smoked and oral forms of THC - oral forms produces longer effects
Cannabidol (CBD) and what’s it responsible for?
- most of the medical effects attributed to marijuana - particularly pain relief
THC vs. CBD
- CBD has little effect on learning and memory (contrast to THC)
- CBD has anti-anxiety effects while THC suggested to increase anxiety
- CBD potentially has anti-psychotic effect which may counter the psychotic effects of THC
- CBD has little effects in producing drowsiness while THC is know to produce this
cannabis smoke vs. tobacco smoke - what is the general consensus - which is more harmful?
- marijuana smoke has more and higher concentrations of harmful constituents than tobacco smoke
- more CO, tar and microscopic damage to the airways bc its unfilited and the smoke is held in the lungs longer
THC and cognitive and motor function
- deblitating effect and strong potential to impair driving ability
THC and tasks measuring memory, divided and sustained attention time, reaction time, tracking and motor function
- dose dependant reduction
Short-term/working memory
- involves using information necessary for the completion of the current version of an activity or task
Long-term/reference memory
- involves using information relevant to the general performance of an activity or task
THC and Memory- which is impacted the most?
- short-term memory is particularly impaired, while there are few effects are on long term memory
The 8-Arm Radial Maze Tasks - what would be a short or long term memory error? What was concluded?
- during spatial training, the same 4 arms were always baited
- once the baited arm was taken it was not replenished until the next training session
- Working memory error: if the rat already visited a baited arm that no longer has food
- Reference memory error: if the rat visited an arm that was never baited
- animals given THC were slower to learn a task than nondrugged rats and those who had learned the game would show more working memory errors
What part of the brain does THC impact?
- reduces cholinergic neurotransmission in the hippocampus (the brain region that is rich in cannabinoid receptors)
cholinergic nervous system
- involved in learning and memory
hippocampus
- involved in memory
- actual damage in hippocampal neurons in rats following exposure to THC
Pope and Yugelum-Todd study
- examined the cognitive functioning of heavy and light marijuana users
- found that heavy users had more difficulty in sustaining/shifting attention, less able to learn and remember a list of words and made more errors in sorting cards were changed without warning
Bolla et al. study
- examined neurocognitive effects of heavy marijuana use over a longer abstinence period
- as the number of joints smoked per week increased, performance decreased on tests measuring memory, executive functioning, psychomotor speed and manual dexterity
- decreased neurocognitive performance even after 28 days of abstinence but unclear if this would resolve
Bllock and Ghoniem study
- identified a group of smokers who all had taken an IQ test in the 4th grade
- results show that heavy users had a significant deficiency in verbal and math abilities and impaired memory
Lane et. al study
- examined the effects of marijuana and working memory in humans using a delayed matching to sample task (DMTS)
- concluded significant impairement of DMTS performance was seen with both doses of marijuana and the magnitude varied in length of delay interval
Cannabis and pregnant women
- 7% of pregnant women use marijuana
- among younger women (teen-24) 20% use it
- maternal cannabis smoking is associated with lower birth weight
- limited evidence of maternal complications and infants sent to the NICU
- insufficient evidence to support that it leads later outcomes in the offspring
- doesnt produce as much adverse teratological effects that alcohol produces but there is some risk for effects so just dont use it
Endogenous cannabinoid receptor sys
- many functions like appetit, pain, mood and memory
- both in animals and humans
Anandamide
- Endogenous cannabinoid sys is normally activated by a naturally occuring cannabinoid ligand
- agonist
what 2 cannabinoid receptors have been found and which one only impacts the CNS?
- CB1 and CB2
- CB1 only impacts the CNS and thus is most important for the psychoactive affects of THC
what neurotransmitters are the receptors involved in modulating or controlling?
- thought to be presynaptic
- reduce acetylcholine release in hippocampus (learning and memory effects)
- increase dopamine release in the VTA by reducing GABA
- reducing glutamate (interfering with long-term potentiation in learning)
is marijuana linked to genetics?
- research provided evidence that subjective reactions may be under genetic control
- identical twins show higher congruence for the effects of the THC than do non-identical twins
Anadamide and THC
- both agonists and occupy the CB1 receptor and produce neural activity
Acomplia (rimonabant)
- cannabinoid antagonist
- block the rewarding effects of THC when you block the CB1 receptor
- discontinued bc of the harmful psychotic side effects
operant self-administration paradigm
- animals are surgically prepared with chronic indewelling catheters
- animals are placed in a Skinner box with a lever from the wall and with a certain number of presses on the lever a small amount of the drug will be released
- controll for this is substuting saline with the drug
- in order for a drug to be considered as having a positively reinforcing properties it must maintain responding at levels higher than those of saline
conclusions from the graphs
- monkey did not press when the only consequence was saline, but that it did press when it received THC infusions
- monkey stops pressing the lever but when THC is again the result of the pressing the monkey goes back to pressing the lever
- the monkey that presses the lever and now get saline instead of the drug this is known as operant extinction
extinction bursting
- common effect seen in operant extinction
- period where the frequency of behaviour goes up for a treatment for a certain period of time then drops (agression is seen here)
are there any approved medications for the use in treatment of marijuana use disorder?
NO
up to what % of American who use marijuana have some level of marijuana use disorder?
30%
in 2015 it was estimated that __ Americans had some level of MUD (marijuana use dirsorder) and the risk for MUD is __x greater if the user starts before the age of __. It is estimated that __% of all drug treatment in the US have marijuana as the primary drug. What is the typical profile?
- 4million
- 7
- 18
- 16%
- white, male and young
It is estimated that __% of all drug treatment in Ontario have marijuana as the primary drug. What is the typical profile?
- 13%
- male, single, less than 20 and in high school
it’s estimated that __% of recreational drug use will develop into dependence or addiction
- around 10%
what helps treat MUD?
- no specific treatment but the same types of psychotherapeutic interventions help (ie. cognitive/behavioural restructuring, relapse prevention, situational self-efficacy etc)
- a very high success rate soon after treatment
what is concluded about treating MUD?
- many patients don’t show a positive treatment response, indicating that marijuana dependence is not easily treated
- problem is with what led to the drug use, not the drug use itself
what has been shown in laboratory studies regard tolerance and THC and humans?
- virtually all the effects of THC in humans have tolerance including self-reported intoxication
do most recreational users develop tolerance, why?
- development of tolerance requires high blood levels maintained for an extended period of time so most recreational users will not develop a tolerance
- taking periods of abstinence might reduce tolerance
females, THC and tolerance?
- females are initially more sensitive to THC effects, show greater development of tolerance to THC effects and exhibit withdrawal symptoms reflecting THC physical dependence than men are
what is the argument following THC and withdrawal?
- with the appropriate dosing or by the use of a THC antagonist, a clear withdrawal syndrome occurs after the following chronic ingestion of THC
Withdrawal symptoms in humans
- hot flashes
- sweating
- runny nose
- stomach pains
- loose stools
- hiccups
- loss of appetite
- disturbed sleep
- aggression
-“inner unrest”
“craving” marijuana
