Final Flashcards
Cannabis plants
2 distinct types, sativa and indica
cannabis sativa
-slimmer leaves
medium THC content when grown in the wild
-described as producing a “cerebra energetic high”
tends to have higher cannabidiol content than indica (which is important for healthy use)
cannabis indica
- tends to have higher THC content when grown wild, and lower cannabidiol content
- high described as “body stone and couch lock”
- has strong, skunky smell
cannabinoids
-unique to cannabis plants
-highly lipid soluble, so are often delivered in oil form
=delta-9 THC is the only psychoactive one (linked to the high recreational users desire); others do seem to influence or modulate the high though even if they don’t produce it
terpenes
another class of compounds found in cannabis
- give the distinctive skunky smell
- contribute to the overall experience of being high (may modulate, some may even have their own pharmaco properties, but not thought to directly produce high)
- ex. myrcene is implicated in muscle relaxation and sedation
phytocannabinoids
(cannabinoids that occur naturally in the cannabis plant)
THC (tetrahydrocannabinol)
-responsible for some medical effects (huge collection of anecdotal reports but little clinical evidence)
-causes cognitive impairment, risk of psychiatric issues w acute and chron use
-have good understanding of how/where it acts in body
CBD (cannabidiol)
-anti-psychotic and anti-anxiolytic effects (seems to oppose some THC effects)
-no cognitive psychiatric issues
-some medically useful effects (ex. approved for seizure treatment)
-causes grogginess, sleepiness, mild impairment
-poor understanding of where/how it acts in the body
cannabis use: recreational vs medicinal
recreational:
-high THC content, CBD content not a concern but typically low, and is used with the aim of getting high
medicinal:
-low THC, high CBD, no high produced
when it comes to CBD vs THC content, we typically see that as one goes up, the other goes down
- balanced content is ~10% CBD:10% THC by total weight
- health experts agree that a 20-30% by weight blend of THC will lead users down a path of high psychiatric risk
cannabis
comes from the cannabis plants
- females produce a stick sap called resin; it’s meant to trap pollen from males, but also contains concentrated active ingredient
- found at highest conc in flowering tops of the plant, less in the leaves and v little in the stalks
- glandular hair-like structures all over the plant contain the resin in little bubbles, and are called trichomes
- goal in growing is to maximize the production of that sticky resin
marijuana
the dried leaves and flowers of cannabis plants (also has all the bad stuff though, like seeds and stems)
- with basic cultivation methods, THC range is 2-8%, but can reach 20% with sophisticated techniques such as hydroponics
- canada is a next exporter, and production is predominantly in BC, also QC and ON
- overall potency increase from 4% in 19995 to 12% in 2014
sinsemilla
- a variation on cannabis plants
- marijuana (dried leaves and flowers) from seedless, unpollinated plants
- if you stop pollination, the energy those plants would have put into making seeds instead goes to production of resin and therefore cannabinoinds
- THC conc ranges from 7-20+ %
skunk
- a cannabis plant variation
- typically a hybrid with high THC conc (7-20%, same range as sinsemilla)
- has distinctive strong smell, and very potent
- linked to all kinds of psychotic episodes (in UK, strong link btw emergence of psychosis in teens and skunk use)
hashish
- preparation from cannabis plants
- concentrated resin from leaves (therefore has few-if any-leaves or other plant parts if it’s high quality stuff)
- depending on purity, THC conc ranges from v low up to 70%
- packed into bricks of varying consistency (depends on moisture content) and oxidation can cause colour change
butane hash oils
- if done right, you can get up to 90% TCH by extracting it from plants into a solvent such as butane
- the purity of the product changes the consistency (budder is lower quality and pasty, then crumble, the shatter, which has the texture of peanut brittle and is the highest purity/most desirable)
- once you have an oil, you heat it to drive off the butane, but it’s hella flammable and can cause a lot of damage
dabbing
method of consuming butane hash oil products
- take a v small amount of the ultra conc’d product, heat to vaporize, then breathe in the blend of THC
- bc of the high conc (THC 80+%), a single inhalation can be equivalent to multiple joints
- many users feel it’s a cleaner way to use because you avoid combustion (so you’re less likely to inhale dangerous planar HCs)
dangers of butane hash oils
- production uses highly flammable gas
- heating process while smoking requires butane torches
- butane contamination in poorly made batches
- reports of individuals passing out after a single use
- use linked to greater physiological dependence compared to other types of cannabis
- since high [THC] plants linked to psychosis, fear that its use will result in more cases
THC absorption
- when smoked, rapidly absorbed into blood (enters brain w/in 10s, effects felt w/in 5-10 min; after 30 min most have left the brain but can still be detected in blood)
- depth of inhalation (not duration) affects speed of absorption
- peak THC content varies enormously with depth and frequency of inhalation, which makes it hard to tell ppl exactly how much they can take and still drive
- even at v low blood conc, 2.5ng/ml, reactions are compromised
- naive users have a hard time recognizing when they’re high
- v lipophil, they have trouble getting through the liquid that covers GI cells; baking in foods with added oil helps
- oral ingestion needs higher does than smoking for same effects, but lasts longer, likely because of the formation of an active metabolite 11-hydroxy THC
THC metabolism
- THC has a half life of 19 hrs
- metabolites have half lives of 50+ hours
- primary metabolite is 11-hydroxy-delta-9-THC which is psychoactive and probably contributes to overall effects
- metabolism is mostly in liver, and also lungs
- also see buildup in body fat (esp in chronic users) as the high lipophilicity of the molecule and its metabolites allows fatty tissue to remain them, maybe even for weeks or months
- if taken orally, there is significant first pass metabolism, so see a higher conc of 11-OH-THC
cannabis-psychological effects
- hilarity, euphoria, well-being/joyfulness, mellowness
- mundane thoughts take on great significance and unconnected events suddenly seem connected
- deficits in tasks requiring concentration, attention, vigilance (but could be just that they don’t care abt pleasing a researcher)
- cognitive effects most heightened in infrequent users (like w alcohol)
- amotivational syndrome (possibly due to decreased DA levels in chronic heavy users, esp if started young)
- short term memory effects (ex. disruption of train of though, possibly from inhib of Ach release in hippocampus)
- in some users, anxiety, panic, dysphoria-> possibly dose/experience related
physiological effects
- increased heart r8 as sympa. tone increases and para tone decreases -> tolerance can lead to bardycardia (lower than normal heart r8 when not using?)
- increased BP (generally only in acute use, BP may be low in chronic users)
- reddening of eyes from dilation of small blood vessels
- sensations of intense hunger
- relaxation of muscles (may be good for treating MS, a condition characterized by uncontrolled, painful tightening of muscles, also some evidence that, at least in periph, some cannabis products may prompt re-myelination)
- decreases eye fluid pressure (maybe good to treat glaucoma, condition of high fluid pressure in eye that can damage retina and optic nerve)
- analgesia (acts at CB1 receptors in PAG (periaqueductal grey), brain region involved in pain pathways)
endocannabinoid system
- the endogenous cannabinoid system modulates NT release and is involved in pain, hunger, learning and memory
- communicate by retrograde neurotransmission (endos travel from postsyn cell and bind to receptors on presyn terminals)
examples: anadamine (AEA), 2-arachidoyl glycerol (2-AG), naturally synthesized in the brain from membrane lipids - they decrease excitability, inhibiting NT release from presyn D1 receptors
cannabinoid receptors
-coupled to G-proteins that decrease cAMP lvls by inhibing adenylate cyclase
-normally activated by endocannabinoids
two types:
CB1-primarily in CNS (one of the most common receptors), presyn, activation inhibs Ca influx, stims K efflux; net effect is inhibition of NT release
CB2-primarily outside CNS, may be immunomodulatory
Rimonabant
- a CB1 receptor antagonist, or inverst agonist
- drops receptor activity below baseline, and could be used to prevent the feeling of hunger
- tried as an anti-obesity agent, but people became depressed, because endogenous cannabinoids are involved in mood
cannabidiol binding sites
- either doesn’t at all or binds only weakly to CB1/CB2 receptors
- a ‘promiscuous’ ligand w low affinity at multiple receptors
- at high doses, seems to indirectly antagonize CB1
- CBD can act as an agonist at TRPV (transient receptor potential vanilloid) channels which are found in pain sensing neurons; seems to activate and then desensitize them, preventing signaling
- > may be contributing to analgesic effects
- 5HT1A agonist and 5HTs antagonist: minimize NT release and nausea respectively, may also be a potential antidepressant as it acts on serotonin receptors
- unknown how it stops seizures
THC and DA
- it’s thought schizophrenia is linked to excessive DA release
- in study where patients inhales 8mg, an estimated 136% increase in DA levels in the NAc was measured 45-85 min after admin
- another showed 10 mg dose induced no measurable DA release, but it was taken orally
- increase DA release likely due to inhib of GABA release in VTA