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HSCI180 CH 15-16 Cannabis & Performance Enhancing Drugs.docx

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Simon Fraser University
Health Sciences
HSCI 180
Julian Somers

Chapter15 Cannabis Cannabis, the Plant  Marijuana = a preparation of leafy material from the Cannabis plant that is smoked o Classified separately because its effects are varied and complex. Effects it produces in most users are sufficiently different from the effects of depressants, narcotics, and hallucinogens to merit its separate classification  Sedation? Pain relief? Hallucinations (in large doses)?  Three Plant species o Cannabis sativa (from Asia, now worldwide)  Fibers to make hemp  Grows as a weed in the U.S. and Canada  A lanky plant 5.5 meters o Cannabis indica (many parts of world)  Grown for its psychoactive resins  1 meter tall  *Potency varies depending on plant genetics and environmental conditions o Cannabis ruderalis (only Russia) Preparations  THC Concentrated in the resin, most in flowering tops (buds), less in leaves, little in stalks  3 Traditional preparations in India  1) Hashish / Charas o Most potent, pure resin from leaves/stems (3-8-20%) o Less pure depending on how carefully the resin has been separated from the plant material o Manually scraping resin too tedious; More efficient method involves boiling the plants in alcohol, filter, liquid evaporate down to a thick dark substance ―hash oil‖  Potency varies but can contain more than 50% THC  2) Sinsemilla / Ganja o Consists of dried flowering tops of plants with pistillate flowers (female plants) o Male plants removed, female pollinate & put energy to seed production, give more potent or ―high grade marijuana‖ (7-12% THC)  3) Bhang (liquid form of marijuana) o Weakest, entire remainder of plant, after removing top, dry and grind into powder, mix into drinks/candies o Rare in North America, similar to low grade marijuana with leaves (less than 1% THC) Early History  Earliest mention: Chinese pharmacy book (2737 BC)  Social use of the plant had spread to the Muslim world and North Africa by AD 1000 o ―Hashishiyya‖ religious cult carried out political murders (assassins) o Story of cult spread in works by Marco Polo (1299) and Boccaccio (1350s) o Hashish use mentioned frequently in The Arabian Nights USA Drug Policy  1900 little use; 1926 news link weed to crime  1936: state had law regulating  Regulation efforts base on concerns about use/resultant behaviour – NOT direct evidence linking weed w/ crime or violence  Why prejudice? Use associated with lower class, recent immigrants Reference in literature to murdering cult (shaky factual grounds), individuals did not commit the crime under influence, but rather received as a reward Marijuana Tax Act of 1937  Grower, distributor, seller, and buyer were taxed o State laws made possession and use of Cannabis illegal per se o 1969: U.S. Supreme Court declared the Marijuana Tax Act unconstitutional  After tax – cost increase significantly  Continue reports that weed has no harm – but substantial disagreement over interpretation  1950s and ‗60s – use increase, symbol of youthful rejection of authority, new era of personal freedom  1970s tried to decriminalize, but 1981 Reagan ‗get tough approach‘ Canada Drug Policy  Since passage of Opium Act (1908), Canada has a strict drug control policy.  Till the late 1950‘s Canada‘s illicit drug policy = one of most punitive in world  1960-1970 dope fiend mythology discredited because many middle class youth uses without being crazy  The Le Dain Commission (1969) - recommended the gradual withdrawal of criminalization of illegal drugs, greater leniency for crime of possession, abolishing imprisonment, possession of weed should not be crime  2002 Liberal party bill 38 – decriminalize small amounts – but conservative elected and bill did not pass Medical Marijuana Access in Canada  2001, allow for medial illness  Category 1: end of life symptom / serious medical conditions (AIDS, cancer, multiple sclerosis, spinal cord injury)  Category 2: if a specialist confirms that conventional treatments have failed.  Can grow, or designate person to grow Supply, Distribution and Trafficking in Canada  Indoor or outdoor – but indoor more common due to greater control, larger yields, higher THC level, avoid law enforcement  2009 report on Illicit Drug Situation in Canada by RMP = amount produced exceed domestic demand, organized crime export to foreign market  Cultivation and Production predominantly in BC, Ontario and Quebec  2009, seized ~ 34k kg of marijuana and ~ 1.8 million marijuana plants  Some imported from Jamaica, US, Europe and Asia o Morrco, then Afghanistan – largest hash supplier o Pakistan – primary transit/source  to Toronto Airport (Most seizures) o Jamaica – primary supplier for hash oil  Grow- Ops worth $17 million and set by organized crime groups have been busted in Calgary area Prevalence of Use  CADUMS Canadian Alcohol and Drug Use Monitoring Survey  More males than females, average age of initiation is 15.6 years old, most province have 10.6% use  Peak 1978, drop 1993, raise till 2005 (increase and decrease perception of risk)  Weed = most consumed illicit drug in world  Compassion clubs – allow sale and use, self-regulated, but usually have physician letter  but eventually ban by health Canada, as they are the only organization that can supply Pharmacology Cannabinoid  400 chemicals, 66 are unique to cannabis, called ―cannabinoids‖ o Active agent: delta-9-tetrahydrocannabinol (THC)  isolated in 1964 o Active metabolite = 11-hydroxy-delta-9-THC Absorption, Distribution, Elimination  Smoke = rapidly absorbed, to brain, then to body o Peak at 5-10 min, Out of brain in 30 min o Half life 19 hours (metabolites 50 hours) o After one week, still have 25-50% of thc/metabolites, complete eliminate in 2-3 weeks  Oral o Absorb slower, liver transform to 11-hd9thc, before going to brain, so less and takes longer o Peak at 90 mins  High lipid solubility of THC and its metabolites o Selectively taken up and stored in fatty tissue, to be released slowly o Cant monitor THC levels and relate to effects o Unsure of long lasting low concentration effects on brain/body Mechanism of Action  Anandamide 1992 discovered natural substance in brain tissues with marijuana like properties  Endogenous substance isolated from brain tissue with marijuana-like effects  Bind to two receptors = CB1 receptor / CB2 receptor  CB1 receptor = found primarily in the brain but also unusually widespread throughout the body o High density of CB1 receptors in specific brain regions  Basal ganglia (movement coordination)  Cerebellum (fine body movement coordination)  Hippocampus (memory storage)  Cerebral cortex (higher cognitive functions)  Nucleus accumbens (reward) o Rimonabant, a selective CB1 receptor antagonist, is being tested  Shows promise in reducing food intake and helping people quit smoking  Concerns due to side effects such as depression and anxiety  CB2 receptor found mainly outside the brain in immune cells o Potential role of cannabinoids in the modulation of the immune system Physiological Effects  Cardiovascular effects o Increased heart rate (dose dependent – more thc more elevation) o 10m in for smoking, 90 for oral o No clear evidence of damage on CVS – but people with CVS disease should not use  Pulmonary effects o Bronchodilation is seen following acute exposure to marijuana o Heavy marijuana smoking over a long period could lead to significant impairment of pulmonary function  Reddening of the eyes  Dryness of the mouth and throat Behavioural Effects  Subjective Effects o Effects include euphoria, ―high,‖ mellowness, hunger, and stimulation o Peak 5-10 min, last 2 hours o Dose dependent – more thc = more effects o Regular smokers can recognize real/placebo o Infrequent smokers – experience more intense effects, high dose may cause negative effects (mild paranoia, hallucinations)  Cognitive Performance (to infrequent users) o Slowed cognitive processing o Impaired short-term memory o Impaired inhibitory control o Loss of sustained concentration or vigilance o Impaired visuospatial processing  Cognitive Performance (to frequent users) o Less dramatic effects, maybe tolerant to some but not all cognitive effects o Slowed cognitive processing consistently seen  Effects on long-term cognitive functioning are more difficult to predict – controversial findings  Food intake: increase appetite and food intake – unclear if chronic marijuana users are overweight  Verbal behavior: Verbal exchanges decrease, nonverbal social interactions increase Medical Uses of Cannabis  Oral TCH (dronabinol; brand name Marinol) o Treat nausea/vomit for cancer patients w/ chemotherapy o AIDS/cancer patient stimulate appetite  Sativex - buccal spray, adjunctive agent for MS patients + as an adjunctive analgesic for cancer pain relief  Nabilone = synthetic cannabinoid w/ antiemetic properties (cancer vomit nausea)  Can alleviate symptoms of spasticity & provide relief & sleep for patients w/ multiple sclerosis  Epilepsy - Reduce seizure frequency but may promote in others  CAMH recommends that cannabis possession be considered as a civil violation Causes for Concern Abuse and Dependence:  Tolerance – develop with high doses used regularly o Cognitive impair develop quicker than heart rate (so long time smoker less cognitively impaired but heart still beat fast) o Different effects develop at different times  Withdraw o DSM-IV: No listing of cannabis withdrawal, BUT o Research suggests an abstinence syndrome does exist **majority does not experience** o Not life threatening but unpleasant  Negative mood states–anxiety, irritability  Disrupted sleep, Decreased food intake  Aggressive behavior (in some cases)  Begins about 1 day after the last dose  Lasts 4 to 12 days  Abuse potential has been shown (when injecting more THC) o Humans/animals will self administer, especially higher dose o Oral – less abuse potential, perhaps due to late onset o Influenced by social factors – more likely use Toxicity Potential  Acute physiological effects - little o Increase heart rate – not a risk, unless is someone with pre-existing CDV disease o No human overdose deaths have been reported w/ cannabis alone  Chronic lung exposure = UNCLEAR implications o Marijuana smoke contains many—but not all—the chemicals found in tobacco smoke (tar, carbon monoxide, hydrogen cyanide, Nitrosamines, Benzopyrene (carcinogen! More in weed than cigarettes) o Marijuana cigarettes not filter – get more smoke, hold it longer o Most users smoke less weed than tobacco users smoke o No direct evidence w/ lung cancer  Reproductive effects - unclear o Reduced testosterone levels in men, decrease sperm (but still at normal levels) o Reduce birth rates? But mom also smoke and drink – unclear associations  Immune system effects - unclear o Some say reduce immunity – maybe increase mortality but no data shows relationship  Amotivational syndrome - lack motivation, poorer relationship – lab data do not support  Psychosis – little evidence it triggers, but yes if already have problems o Some researchers are collecting data that they claim shows that marijuana causes psychosis o Some studies have found a correlation between marijuana use and psychotic symptoms. o Participants admitted to having at least one psychotic symptoms. o It is possible the people had psychotic symptoms prior to using marijuana. o Since marijuana users typically use other psychoactive drugs, it is difficult to disentangle the influence of other drug use on the psychotic symptoms o There is evidence that marijuana can increase the likelihood of psychotic episodes in individuals with a history of psychiatric problems.  Driving ability: Research findings mixed o Laboratory studies = significant impairment in infrequent users o Epidemiological studies = Little evidence if use marijuana alone = more accident  Anxiety/Panic o Infrequent users - fear of loss of control and fear that things won‘t return to normal o Some require sedative, best method is just ‗talking down‘, reminding person Marijuana and American Society  Big issue – 14 states have medical marijuana  1960-1970 shift in attitude- found out government lied about drugs and rejected gov info  Seniors smoke peak 60% 1970s  Changing attitudes toward decriminalization o 1972 report recommended decriminalizing possession of small amounts for personal use and casual distribution of small amounts without monetary profit o 1973 alter law – possession now civil, not criminal – save CJS money, use went up but not substantial  2009 change and put back into schedule 1  Four factors that push decriminalization o Increase evidence – not toxic as once thought o Economy crash, too much money spent of stopping drugs o People believe government could tax, mak
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