Lecture 1 and 2 Flashcards
Psychoactive drugs:
Any single chemical compound that interacts with the function of our central nervous system [i.e. the brain and spinal cord], and changes subjective experience or behaviour, or both. Also described as mood altering, as they can change the way we think, feel or act.
Classification of psychoactive drugs:
They are classified according to the effects they have on the central nervous system.
Depressants:
Supress, inhibit or decrease central nervous system activity. Drugs in this category include alcohol, sedatives, hypnotics [sleeping pills], and opioid drugs such as heroin, morphine and methadone. Generally, if taken in small doses, these drugs produce relaxation or drowsiness. In large doses they can lower respiration and heart rate to the point of unconsciousness or death.
Stimulants
Enhance or increase activity in the CNS. These drugs typically increase blood pressure and heart rate, increase respiration and generally increase arousal. Drugs in this category include amphetamines. MDMA, ecstasy, cocaine, caffeine and nicotine. In low doses they can increase energy, feeling of well-being and alertness. Heavy use can result in irritability and insomnia. Stimulants can also produce delusions and hallucinations.
Hallucinogens:
Sometimes referred to as psychedelics, act on the CNS to alter perceptions, thinking, feelings and sense of time and place. Some of the adverse effects include unpleasant and frightening hallucinatory experience, post-hallucinogen perception disorder [flashbacks], delusions and paranoia. Drugs in this category include LSD, mescaline and psilocybin [magic mushrooms]. Cannabis may have hallucinogenic and or depressant effects.
Most commonly used drugs:
1) Cannabis
2) Ecstasy
Self-medication hypothesis:
The use of unprescribed medications or illegal drugs to relieve stress, anxiety or other distressful psychological states.
Normative drug use:
Expectations about drinking or other drug use based on perceived use by peers. For example, if a young person forms the view that everyone is using a drug, this may increase the likelihood that they will also use it to conform to what they perceive to be the norm. Perceptions of use are often far greater than actual use.
Intoxication:
A condition that follows psychoactive drug use, evidenced by disturbances in the level of consciousness, cognition, perception, judgment, affect or behaviour. Intoxication depends on the type and dose of a drug, tolerance to the drug and personal expectations about the effects of the drug.
Tolerance
This refers to the way the body gets used to the repeated administration of a drug, so that higher doses are needed to maintain the same effect.
Addiction
A term synonymous with dependence. The continual and excessive use of a drug despite the harms that it causes to the individual and others, and repeated failed attempts to stop or limit use.
Dependence liability:
The variable risk of developing dependence associated with different psychoactive drugs. For example, at a population level, the risk of developing cannabis dependence is lower than the risk associated with alcohol or cocaine use.
Maturing out:
The process whereby people who experience serious drug problems, including dependence in their younger adult years, reduce their drug intake and associated problems as they mature.
Relapse
A return to drug use or drinking after a period of abstinence, often accompanied by reinstatement of dependence symptoms. Some writers distinguish between relapse and lapse fan isolated occasion of drug use or a slip.
Chronic relapsing disorder:
Drug dependence is often perceived to be a long-term or life-long condition characterised by periods of uncontrolled use, treatment, abstinence or controlled use and relapse. This is the case for some people, but the majority do not seek treatment and resolve their dependency issues themselves.
Drug misuse:
This refers to use of a drug in a way that is likely to cause harm, usually associated with legal drugs and differentiates non-problematic from problematic use.
Harmful drug use:
A pattern of drug use that is causing physical or psychological damage to health (such as hepatitis from injecting or depression associated with alcohol use.). It also often results in social consequences.
Substance or drug dependence:
A maladaptive pattern of substance use leading to clinically significant impairment or distress, as manifested by a need for increasing amounts of the substance to achieve intoxication, the need to continue to take the substance in order to avoid withdrawal symptoms, unsuccessful attempts to stop or cut down the drug use, and continued use despite harmful consequences.
Substance use disorders:
The term used by the American Psychiatric Association (2000) in the Diagnostic and statistical manual to describe a condition that includes substance abuse and substance dependence.
Alcoholic
A term consistent with a disease theory of dependence that describes a person experiencing alcohol dependence.
Addict
A person who is addicted to or dependent on a psychoactive drug. It implies a lack of control over use of the drug.
Brief History of AOD in Australia:
• Before colonisation, Aboriginal peoples had only limited contact with psychoactive substances – some plant-based stimulants and depressants used.
• First Fleet: medicines, drugs and hemp seeds for protection “warm climates and tropical diseases”
• For 150 years early governments actively supported the growing of hemp
– land and other grants
– popular as a medicine
– used as an intoxicant by members of the literati
• Drug use in the late 1800s was mainly opium and cocaine-based stimulants
– used by doctors / nurses, the middle-upper class, housewives (for depression + menstrual pain)
– and then later by Chinese immigrants.
Alcohol
– Heavy drinking has been a ‘cultural norm’ since colonisation.
– 1808: Rum Rebellion
– 1830s: ‘the Temperance Movement’ peaking during World War I/Great Depression
• Prohibition in states of Australia
• 1837, laws were passed to prevent Aboriginal access to alcohol
– “six o’clock swill”
7 Themes common to drug wars:
- The notion of public menace
- Political interests
- Increased criminal justice response
- Influence of media coverage
- Portrayal of drug use as infectious
- The need to protect vulnerable target groups e.g. women and young people
- Aggressive, militaristic terminology
Pharmacology: The effect a drug has on someone depends on the: (3 things)
Person Age Gender Individual health Cognitions/expectations
Drug How it’s taken (Oral, IV, smoked etc…) Amount used Frequency of use Duration of use/history Drug interactions
Environment
Social factors
Pharmacokinetics
has to do with absorption, distribution, metabolism and excretion of a drug, or ‘what the body does to the drug’
Pharmacodynamics
has to do with the biochemistry, pharmacology, and effects of the drug, or ‘what the drug does to the body’
Absorption
Via the skin (e.g. Patches, absorbed through skin into circulation)
Oral (Small intestine – Liver – Circulation)
Smoked (Mouth/lung lining – Circulation)
IV (Directly into circulation)
Distribution
Organs with high blood flow first (Brain etc…)
Fat, muscles and skin later
Drug dependence/neuroadaptation
After period of continual use can become dependant on a drug
Social, psychological, not just physical dependence
Drug tolerance
When dependant, less affected by drug/need more to feel effects
Drug withdrawal
When physically dependant, cessation results in withdrawal
In general withdrawal symptoms have opposite effect of the drug
Cross-dependence
One substance can take place of another to continue physical dependence and avoid withdrawal
Agonist effect
an increase or stimulation the action of a neurotransmitter
Antagonist effect
decrease or inhibition of the action of a neurotransmitter
Dopamine
Dopamine – Neurotransmitter related to reward/pleasure
Pharmacokinetocs- What the body does to the drug: Half life
Time for drug in blood to reduce by 50%
Short half life/short action more likely to be abused (e.g. Cocaine and Nicotine)
Pharmacokinetocs- What the body does to the drug: Metabolism and excretion
Mostly via urine, some through lungs or gut
Pharmacodynamis- What the drug does to the :
SYNAPSES
Brain - millions of pathways (nerves) similar to a mass of electrical wires
Communication using chemical messages (neurotransmitters)
Everything that we think, feel and do are the result of these chemical communications
PharmacologyPharmacodynamics - What the drug does to the body
Many drugs act by mimicking normal neurotransmitters
Occupying receptor sites and sending “false” messages
Agonistic Drug Effects (6)
1) Drug increases the synthesis of neurotransmitter molecules (e.g. by increasing the amount of precursor
2) Drug increases the number of neurotransmitter molecules by destroying degrading enzymes
3) Drug increases the release of neurotransmitter molecules from terminal buttons
4) Drug binds to autoreceptors and blocks their inhibitory effect on neurotransmitter release
5) Drug binds to postynaptic receptors and either activates them or increases the effect on them of neurotransmitter molecules
6) Drug blocks the deactivation of neurotransmitter molecules by blocking degradation or reuptake
Antagonistic Drug Effects 5
1) Drug blocks the synthesis of neurotransmitter molecules (e.g. by destroying synthesising enzymes)
2) Drug causes the neurotransmitter molecules to leak from the vesicles and be destroyed by degrading enzymes
3) Drug blocks the release of the neurotransmitter molecules from terminal buttons
4) Drug activates autoreceptors and inhibits neurotransmitter release
5) Drug is a receptor blocker; it binds to the postsynaptic receptors and blocks the effect of the neurotransmitter
Types of drugs: Depressants
Slow down brain and body
May cause initial high/euphoria
Impair coordination
Some appear to cause emotional depression
Small doses: relaxation, drowsiness and loss of inhibitions
Large doses: can cause loss of consciousness, respiratory inhibition, and even death
Particularly dangerous when drugs are combined
Depressants- Alcohol and Benzodiazepines
Mechanism of action:
GABA agonist – reduces overall brain activity
Glutamate antagonist – excitatory function reduced (effect of BZD on this system is not clear)
So, overall depressant effect
Benzodiazepines focussed on anxiolytic or sedative effects depending on type
Also differences in half-life and strength
Benzodiazepines and Alcohol are cross-dependant due to the similar action on GABA system
Alcohol
Immediate effects after a few drinks
happy, more relaxed, less concentration, slow reflexes, less inhibited
A few more
disinhibited, more confidence, less coordination, slurred speech, intense moods
A few more
confusion, blurred vision, poor muscle control
More still
nausea, vomiting, sleep
Even more
coma or death
Long term health effects of heavy drinking
Long term health effects of heavy drinking
Nervous system
Brain damage – effects on memory (Korsakoff’s syndrome)
Liver
Damaged by alcohol processing – (Cirrhosis, Liver Cancer)
Withdrawal related risks
Seizures and in worst case death
Other health effects
Heart, Muscles, Pancreas, Sexual organs, Skin, Stomach, Intestines etc…
Emotional/Psychological/Social
Korsakoff Syndrome
Caused by brain impairment due to chronic, heavy alcohol consumption severely depleting vitamin B1 (thiamine)
Effects the formation of new memory
Cannabis
THC is the main active ingredient Binds to cannabinoid receptors Interferes with normal functioning of brain Cerebellum Affects coordination Hippocampus Affects memory Cerebral cortex Affects thinking
Cannabis common effects
THC Common effects Feeling of intoxication Loss of coordination & concentration Increased appetite Reddened eyes Anxiety or panic Hallucinations Paranoia Confusion
Long term effects of cannabis
Long term effects of heavy use
Health Risks
Bronchitis, lung cancer & respiratory disease
Lowered sperm count / irregular menstrual cycle
Brain function
Loss of concentration, memory & learning abilities
‘Amotivational syndrome’
Loss of interest in activities, loss of energy, boredom
Less sex drive
Severe psychotic behaviour (Drug induced psychosis)
Causal link not certain
Medicinal Cannabis Research
Medicinal Cannabis Research
Improvement in seizure disorders, especially in children, pain management, nausea associated with chemotherapy, and some other conditions
Role of CBD – antipsychotic, antidepressant, anxiolytic?
However, controversial due to potential for misuse/inappropriate prescription, and risks associated with cannabis use (e.g. Psychosis)
Also, are there not effective alternative medications for these problems?
QLD health on medicinal cannabis
Conditions that may benefit
Current limited evidence suggests that medicinal cannabis may be suitable to treat:
severe muscular spasms and other symptoms of multiple sclerosis
chemotherapy-induced nausea and vomiting
some types of epilepsy with severe seizures
palliative care (loss of appetite, nausea, vomiting, pain).
There is no evidence that medicinal cannabis is an effective treatment for cancer.
Patients should not:
consider medicinal cannabis as an alternative treatment for cancer
defer their standard treatment in favour of using medicinal cannabis.”
Opiates
Opiate receptors – pain relief Endorphins Affects dopamine (reward effects) Pain relief – Physical and Psychological Overdose risk high Common effects Feelings of well-being or euphoria Pinpoint pupils Sedation Shallow breathing Nausea and vomiting
Long term effects of heavy use of opiates
Health effects Constipation Weight loss / malnutrition Chronic heart / lung conditions Infertility in women Irregular periods Injecting risks Loss of sex drive Dependency The biggest risk with opiate use is overdose The role of Narcan (Naloxone)
Depressants- Inhalants Immediate effects
All areas of the body affected
Can cause serious health effects to body including death
Psychological effects
Such as confusion
Hangovers and headaches can last for several days
Depressants- Inhalants- Long term effects
Significant Long Term Health effects
Tremors, poss of sense of smell & hearing, problems with blood production, Irregular heart beat & damage to heart muscle, Liver & kidney damage
Effects on brain function
Forgetfulness/memory impairment, Inattention/reduced ability to think clearly & logically
Psychological effects
Irritability, hostility, feeling depressed or feeling persecuted
Stimulants
Increase the body’s state of arousal
Accelerate central nervous system
Small doses: increase awareness and concentration, decrease fatigue and amplify positive moods
Larger doses: can cause excessive activity, irritability, nervousness, insomnia, delusions and hallucinations (drug-induced psychosis), convulsions, death
Stimulants- Nicotine
Dopamine agonist – reinforcing
Glutamate agonist – stimulant
Short term effect, small half-life Highly addictive Pros and Cons Improves short-term memory Serious long term health effects of smoking
Stimulants- Methamphetamines
Significantly alters levels of dopamine (extreme agonist) and norepinephrine
Common effects
Speeding up of bodily functions
Dry mouth, sweating, large pupils, headaches
Energetic & increased confidence
Awake & alert
Talkative, restless, excited, trouble sleeping
Panic attacks
Reduced appetite
Anxiety, hostility, aggression
Long term effects of heavy use of methamphetamines
Long term effects of heavy use Health effects Rapid & irregular heart beat High blood pressure Major sleeping problems Malnutrition Injecting risks
Psycho-pathology
Anxiety and tension
Amphetamine psychosis
Hallucinogens
Distort the brain’s perception of reality
Can cause auditory, tactile, or visual hallucinations
Include varying degrees of depression or stimulation depending on the substance
Ecstacy- hallucinogens
MDMA affects serotonin 6-10 hr half life Ecstasy – 3 phases Coming up – Drug starting to take effect Nausea, increased body temp, heart rate increase, difficulty focusing or make sense of what you are seeing, confusion, or panic Plateau – Effects levelling off Heightened sensations, increased energy, confidence, talkativeness, feeling of warmth towards others Coming down – Effects wearing off Flat, depressed, exhausted
High does and long term effects of ecstasy (hallucinogen)
High doses Convulsions Vomiting Floating sensations Irrational or bizarre behaviour Hallucinations Long Term Effects Brain damage? – Serotonin Depression, anxiety, paranoia?
Emerging psychoactive substances
Similar metabolic structures – mimic effects
Sufficiently different to avoid detection – metabolites
Examples:
Cannabis (JWH-018, JWH-073, cannabicyclophexonal) – cannabiniod agonist
Mephedrone (4-methylmethcathinone, 4-methylephedrone) – substituted cathionones
NBOMe (251-NBOMe, 2C-I-BOMe) – psychedelic
DMT (N,N-Dimethyltryptamine) and AMT (α-Methyltryptamine) general tryptamines
Ultimately unknown effects due to wide variety of drugs and subtle variations in chemical structure
Prescription drug abuse
Many opiates, benzodiazepines, amphetamines, and maybe in the near future cannabis, are available via prescription from a doctor
All of these drugs have the same potential for harms as the illicit substances
Prescription drug abuse is a large and growing problem in Australia
Important consideration in the argument about medicinal cannabis…
General trends
Smoking—a significant decline in daily smoking between 2010 and 2013 (from 15.1% to 12.8%);
Alcohol—fewer people in Australia drank alcohol in harmful quantities in 2013
Illicit use of drugs—declines in use of some illegal drugs in 2013, others relatively stable
Tobacco use in Australia patterns of use in australia
In general, smoking gradually decreasing since early 90’s
Daily smoking declined (from 15.1% to 12.8%). Daily smoking rates almost halved since 1991 (24.3%).
Younger peopledelaying the take upof smoking— from average age 14.2 in 1995 to 15.9 years in 2013 (14-24 yo)
average number of cigarettessmoked per week reduced; from 111 to 96
Who smokes the most?
Men more likely to be daily smokers and smoke more cigarettes per week
Females were more likely to have ‘never smoked’
People aged 40-49 most likely to be daily smokers
However, 50-59 age group smoke most cigarettes per week
Patterns of use: Alcohol
In general, drinking in Australia is in recent decline
2016 results necessary to assess this trend
Daily drinking declined significantly between 2010 and 2013 (from 7.2% to 6.5%)
lowest level seen since 1991.
Significant increase in those never consumed a full serve of alcohol (from 12.1% to 13.8%).
Fewer 12–17 yo drinking abstainers increased significantly (from 64% to 72%).
Younger people (14-24) delaying first drink - average age from 14.4 in 1998 to 15.7 years in 2013.
In 2013, fewer people drank in quantities that exceeded the lifetime risk and single occasion risk guidelines
18.2% exceeded lifetime risk guidelines (20% 2010)
(More than 2 st drinks per day on average)
Males were twice as likely as females to exceed lifetime risk
Single occasion risk also declined - 29% to 26%.
(More than 4 st drinks on one occasion)
Men in their 40s and late 20s were most likely to drink at risky levels (32%), 18-24 for women (14.6%).
Fun facts
Tobacco smoking is the single most preventable cause of ill health and death… It is responsible for more drug-related hospitalisations and deaths than alcohol and illicit drugs combined.”
(AIHW 2010)
“Alcohol causes the deaths and hospitalisation of slightly more children and young people than do all the illicit drugs combined…”
Patterns of use in australia: Illicit drugs
Changes in the use of illicit drugs were mixed
In 2013, 42% lifetime illicit drug use
including misuse of pharmaceuticals.
3 million (15.0%) in last 12 months, 2.7 million (14.7%) in 2010.
Significant declines in use of ecstasy, heroin, and GHB
all relatively low rates compared to other illicit drugs
Misuse of pharmaceuticals increased (4.2% to 4.7%)
Use of the remaining drugs relatively stable
Cannabis most commonly used illicit drug:
10.2% recently; 35% lifetime
Males were more likely than females to use illicit drugs (18.1% compared with 12.1%)
People aged 50 or older lowest rates of recent illicit drug use
However, recently shown the largest increase in illicit drug use (8.7% to 11.1% for 50–59yo; 5.1% to 6.4% for 60+)
No significant increase in meth/amphetamine use in 2013:
powder use decreased (51% to 29%), ice (crystal methamphetamine) more than doubled (22% to 50%)
Significant increase in daily or weekly use (from 9.3% to 15.5%), particularly among ice users (from 12.4% to 25.3%)
Patterns of use in Australia: Gender Variations
In general males more likely to use illicit drugs than females, with some notable exceptions
Among 14-17 age group (females)
more likely to have used illicit drugs recently (13.3% vs 15.7%)
Similar to results from previous surveys as well
Why is this gender variation only seen in the 14-17 age group?
Patterns of Use in Australia: Heroin
- 4% of Australians have used heroin
- 2% recently
Recent use of heroin much higher in 1998 than 2013
1998 - males 1.1%, females 0.5%
2013 - males 0.3% and females 0.2%
Patterns of use in Australia: International comparisons of alcohol and tobacco
Worldwide, tobacco consumption in decline.
Australia one of the lowest smoking countries – OECD (Organisation for Economic Co-operation and Development)
Conversely, Australia ranked 14th highest in the world per capita consumption of alcohol
9.8 litres equivalent of pure alcohol per person per year
Up from 7.5 litres in 2003
Equivalent to approx. 500 pints of beer each
Lowest: Turkey 1.3 litres
Highest: Luxembourg 15.5 litres
Patterns of Use in AustraliaCommunity Concern and Support: Tobacco
Support for policies aimed at reducing harm caused by tobacco remained high
Support for stricter enforcement law and penalties for supplying to minors (9 in 10 supportive)
Reduction in concern about tobacco generally
Patterns of Use in AustraliaCommunity Concern and Support: Alcohol
More people thought alcohol caused most drug-related deaths
for the first time was higher than tobacco.
Excessive use of alcohol the drug issue of most concern (4 in 10 people).
Support for policies to reduce alcohol harm
more severe penalties for drink driving (85%),
stricter enforcement of the law against supplying to minors (84%).
Patterns of Use in AustraliaCommunity Concern and Support: Illicit drugs
Meth/amphetamines illicit drug of greatest concern (increase from 9.5% to 16.1%)
Increase in belief meth/amphetamines caused most deaths (4.7% to 8.7%), still lower than heroin (14.1%).
Proportion nominating cannabis and heroin as ‘drug problem’ declined,
Proportion nominating meth/amphetamines and pain-killers/analgesics increased.
Most people try illicit drugs because they are curious (66%),
And continue use to enhance experiences (30%) or for excitement (17.5%).
