cannabis Flashcards
what is cannabis?
Cannabis is one of the most widely used recreational and medicinal drugs worldwide; 150 million people worldwide/day (WHO)
class B
why does people abuse cannabis?
as a normal physiological function, engaging in positive( rewarding) behaviours lead to pleasurable feelings
-drugs represent substitutes for such behaviours
epidemiology of cannabis
cannabus (marijuna) is most abused illicit substance in USA and Europe
can lead to dependency and addiction
50% of users are 25 years of age
abusers experience social, psychological and physical consequences
-financial diffciulties
-low energy
-sleep and memory problems
-low self asteem
-fall in productivity
-low life satisfaction
many patients report withdrawel syndromes upon cessation
Abused forms of cannabis
All forms are derived from the plant itself
See also PM3B lecture on synthetic
cannabinomimeticnovel psychoactive substances
Most common forms are:
Dried flowering tops of the female plant (‘buds’)
Leaves have little cannabinoid content and so are rarely used
Resins and oils
traditionally made from compression of the dried trichomes(‘slate’, ‘black’ etc.)
Now often made by butane-based extraction (‘bubble’)
Some advocates of juicing the fresh plant
Non-psychoactive as cannabinoids are present in the acid form and decarboxylated by drying and/or heating
Routes of administration:unlicensed medical and illicit
the effect can vary depending on the dose and route of administration
inhalation - smoking
orally - food supplements or mixed with food
metabolised to 11-OH- THC in GIT to produce longer lasting, less predictable and more potent effects
dose is not controlled
Routes of administration:licensed medical
what are the applications
-sublingual aerosols
-THC capsules
therapeutic applications
-appetite stimulation in AIDS patient
-MS-related spasticity
-chemotherapy related nausea
-neuropathic pain associated with a chronic disorder
what are longterm toxic effects
Addiction
Altered brain development
Poor educational outcome, with increased likelihood of dropping out of school
Cognitive impairment, with lower IQ among those who were frequent users during adolescence*
Diminished life satisfaction and achievement (determined on the basis of subjective and objective measures as compared with such ratings in the general population)
Symptoms of chronic bronchitis
Increased risk of chronic psychosis disorders (including schizophrenia) in persons with a predisposition to such disorders
Clinical management of abuse
DSM-5 lists ‘cannabis dependece’ or ‘cannabis use disorder’ as a condition requiring treatment.
behavioural:
motivational enhancement therapy (MET)
cognitive behavioural therapy (CBT)
contingency management (CM)
family-based treatment
what is Salvia divinorum
*Family: Lamiaceae. Mint, salvia, oregano, marjoram, lavender, thyme
*Hallucinogenic (leaves)
*Native of Mexican Sierra and used by Mazatecs for ritual purposes
Salvinorin a
moa
dose
effects
moa
Salvinorin a; neoclerodane diterpene
hydrolysed by Salvinorin B
selective and potent-kappa-opioid receptor (KOR) agonist
non-nitrogenous and lipid like GPCR
dose
200-500 microgram dried leaves
strong hallucinogen
effects:
modified state of awareness
short lived inebriant state (1-30min)
intense, bizarre feeling of depersonalization
synaesthesia
visual hallucination
Legal status, applications and risks
legal in most countries
shows rewarding/addictive effects in rat experimental system
no reports of death or toxicity due to overdose
dose is crucial:
low dose - ameliorate pain and mood
high dose- exacerbate these symptoms
what is nitrous oxide?
- gas
-rapid absorption and elimination
effects of nitrous oxide
feelings of euphoria, relaxation and calmness. fits of giggles and laughter
moa of nitrous oxide
CNS effect
analgesia:
enhances release of endorphins by inhibiting interneuronal inhibition of endorphins releasing neurons
-endorphins induce analgesia through opioid receptor activation
euphoria
-induces dopamine release which stimulates mesolimbic reward pathway
anxiolytic effect
-GABA mediated
abuse of cannabis
effects of gas inhalation
Clinically used as an analgesic during dental surgery and childbirth
Effects of gas inhalation:
Dizziness
Euphoria
Bursts of laughing
Dissociation
Sexual performance enhancer
Short acting (minutes; dependent on dose)
