Cannabinoids

Natural and synthetic compounds resembling delta-9-THC

Cannabis Sativa

u best known of the hemp plants

u psychoactive ingredients have a unique combination of effects of several categories

– some stimulant-like effects 

– some depressant-like effects

– some analgesic effects

– some hallucinogenic effects

– some important body effects

Marketable Components

u fiber from the stalks

u psychoactive leaves, flowers, resin

u best fiber plants usually have lower THC - sometimes close to 0%

u growing conditions, genetics, and parts harvested determine concentration

u dose in user also depends on delivery factors

Forms Available

u Marijuana, bhang - leaves, fine stems, some flowers/seeds (~2-6%, but some more potent)(1-2% was the norm in 60’-80’s)

u Sinsemilla, ganja - leaves and flowers from unpollinated female plants (~5-8% or more)

u Hashish, charas - collected and dried resin (10-20%) from female flowers

u Hash oil – a solvent is used to extract THC from hashish (~20-60%)

Active Ingredient(s)

u delta 9 tetrahydrocannabinol (THC) (~50 mg/joint now vs 20mg 20 yrs ago, with 25-50% released in smoke). What you absorb depends on how you smoke (~.4-10 mg)

u There are about 60 related cannabinoids in cannabis – at least 2 others (cannaninol and cannabidiol) have psychoactive effects

Cannabinoid Receptors

u 1990 - Found THC binds to specific receptors in brain

u Receptors widespread in limbic system, cortex, motor system, cord & lymph glands, but not brainstem

u 1992 Discovered natural brain chemical that fits those receptors: anandamide

u So THC is an “anandamide agonist”

u Anandamide receptors are pre-synaptic receptors which decrease the release of other neurotransmitters at synapses 

u Low doses - depressant-like; higher doses-hallucinogen-like

Oral Route vs Smoking

u slower, less complete absorption - harder to “titrate dose” because of 2-3 hr delay in action

u other compounds likely to be absorbed as well - more chance of nausea or “hangover”

Common Body Effects

u red eyes

u droopy eyelids

u dry mouth & throat

u increased pulse, BP

u muscle relaxation & impaired coordination

u irritates lungs, sinuses

u mixed bronchial effects

u dose-dependent effect on appetite

u dose-dependent effect on sexual function

u decreased sex hormones

u decreased temp 

MJ Smoke vs Tobacco Smoke

u similar levels of carbon monoxide & other gases, ~50% more tars & carcinogens

u Lung studies suggest damage from 1-3 joints = that of 5-15 cigarettes

u decrease in ciliated cells that cleanse lungs leading to joint cough and bronchitis

u pattern of smoking different (less often but deeper) - NOT risk-free

u sometimes contains contaminants

u long-term effects remain to be seen

Common Psychological Effects

u Relaxation, sedation

u Euphoria

u Hilarity, labile mood

u Intensifies emotions

u Sensory enhancement

u Impaired short-term memory & learning

u Impaired attention

u Longer reaction time

u Impaired visual tracking & spatial processing

u Impaired temporal ordering of behavior

u Decreased problem solving & judgment

u Altered time perception

u Decreased motivation

u Altered cognition

u Impairments outlast high

Cannabis Impairs Driving

u 40% of those under 30 in accidents have cannabis in their system

u Cannabis users are about twice as likely to be ticketed or have an accident than non-users

u Even greater impairment when combined with alcohol

u Half-life ~ 30 hrs – once again, impairments outlast high

Risks

u Depends on pattern of use

u Short-term: lengthy impairment of driving/performance; increased pulse may be risky to some; affects memory, attention

u DAWN shows ~25,000 emergency room visits involve cannabis each year 

u Long-term risk to lungs; degree of risk to immune, sexual, or brain function still unclear; adverse fetal effects

u Heavier use/higher potency very likely to have adverse behavioral effects

Possible Medical Uses

u Appetite-stimulant, anti-nausea

u Analgesic, euphoric effect to ease suffering

u Reduced intraocular pressure of glaucoma

u Relax muscles/decrease muscle tension in

MS, Tourrette’s and spastic disorders

u Occasionally used for bronchodilation

Estimated Use

u 70 million in US have used sometime

u 17 million in last year

u 10 million currently

u increasing use by middle & high school students (~35% have used, 4.6% daily)

Legal Presciption Cannabinoids

u Marinol (dronabinol) 2.5 mg capsules Cessamet (nabilone)

u most patients prefer marijuana however- faster effects via smoking, able to titrate dose, perceived as more effective

Cannabis Buyers’ Club

u Decriminalization of the medical use of marijuana in some states, but Feds cracking down lately

Dependency?

u Occasional use-no physical dependency May develop a psychological dependency

u High dose regular use can produces tolerance & a withdrawal syndrome (restlessness, irritability, craving, insomnia, aches, sweating, anxiety, depression, nausea, cramping)

u Many users find quitting difficult & seek substance abuse treatment

What change, if any, should be made in marijuana’s legal status?

u Greater availability for medical use?

u If its “medicine”, should it be held to FDA standards for other drugs?

u Greater availability for personal use?

u Will we be seeing a repeat of current tobacco industry problems?

u How should sale/supply be handled?