Addictions symposium Flashcards
- Recognise the universality of substance use and abuse.
- Discuss the distinctions between use, problem use, dependence and addiction.
- Discuss the ways in which substance misuse may impact on the individual, his social nexus and wider society.
- Differentiate between the physical and psychological aspects of addiction.
- Explain the concept of physical drug tolerance and drug dependence. - DONE
- Describe the location and function of the reward centre and recognise that activation of the reward centre by addictive drugs causes the psychological symptom of craving. - DONE
- Recognise that there may be a genetic basis for variation in the strength of the reward centre between individuals.
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Tolerance (the basis of physical dependence) Reward centre (the basis of psychological craving)
Define tolerance
Reduced responsiveness to a drug caused by previous administration
Mechanisms underlying tolerance
- DISPOSITIONAL TOLERANCE
- PHARMACODYNAMIC TOLERANCE
Less drug reaching active site (DISPOSITIONAL TOLERANCE)
- less drug absorbed
- drug metabolised faster
- more drug excreted
Drug has less action at active site (PHARMACODYNAMIC TOLERANCE)
- fewer drug receptors
- reduced signalling downstream of drug receptors
Withdrawing a drug has what effect
The reverse of the acute effect, e.g. opioids have acute effect on constipation but when withdrawn will cause diarrhoea
Acute v withdrawal effect of barbiturates
Anticonvulsant
Convulsions
Acute v withdrawal effect of cocaine
Elevated mood
Depressed mood
Development of tolerance can lead to …
Dependence in order to avoid the withdrawal effects (because while being on the drug, body produces adaptive response to drug so drug no longer works)
Location and function of the reward centre
Location - nucleus accumbent + ventral tegemental area (neurones project from the ventral tegmental area to the nucleus accumbens & prefrontal cortex)
Function - when VTA neurones are stimulated, they release dopamine which causes a sensation of pleasure/reward
Reward pathway (VTA neurones projecting to nucleus accumbens & prefrontal cortex) is activated by what things
Eating
Drinking
Sex
Activation of the reward centre by addictive drugs causes the psychological symptom of craving
They do this by increasing dopamine levels - how do different drugs do this?
- heroin
- amphetamine
- cocaine
Heroin increases firing rate of dopaminergic neurones
Amphetamine increases dopamine release
Cocaine inhibits dopamine reuptake
Psychological craving is a result of stimulation of what pathways in the brain
Reward pathways in the brain
Name 2 stimulant drugs
Cocaine
Amphetamine
Different forms of cocaine and how they’re taken
Coca leaves - chewed or brewed
Cocaine hydrochloride (powder) - snorted or injected
Crack cocaine - smoked
How quickly does it take for the effects of cocaine to kick in
- smoking
- injecting
- snorting
Smoking - almost immediate (very intense but wear out after 15 mins)
Injecting - 15-30 secs
Snorting - 3-5 mins
Symptoms (5)/ signs (6) of cocaine
Elevated mood Increased alertness/energy Increased confidence but impaired judgement Reduced appetite Reduced desire to sleep
Damage to nose + airways Convulsions (seizures) Arrhythmias, MI Hypertension Toxic confusion (delirium) Psychosis
Withdrawal symptoms of cocaine (6)
Depression Irritability Agitation Craving Hyperphagia (huge desire to eat) Hypersomnia (excessive sleepiness)
Is cocaine or amphetamine longer lasting
Amphetamine
Name some examples of opiates (6)
Opium Morphine Heroin (diamorphine) Methadone Codeine Dihydrocodeine
Symptoms (5)/ signs (4) of heroin
Analgesic (i.e. pain relief) Drowsy Elevated mood (euphoria) Nausea/vomiting Constipation
Resp depression
Cough reflex depression
Bradycardia + hypotension (due to decreased sympathetic outflow)
Pupils CONSTRICT
Pathognomic sign of opiate overdose
Resp arrest with a pulse
Side effects of opiates
- first time
- medium term
- long term
N/V
Headache
Phlebitis (inflamed vein)
Anorexia (reduced appetite)
Constipation
Tolerance
Withdrawal effects
Social + health problems
Withdrawal effects of opiates*(opiate withdrawal syndrome)
*worse withdrawal problems out of all stimulant drugs
Craving Insomnia Yawning Muscle pain and cramps Increased salivary, nasal and Lacrimal secretions Dilated pupils Piloerection
Clinical effects of ecstasy (MDMA - 3,4-methylenedioxymethamphetamine) (3)
Euphoria followed by feeling of calm
Increased sociability
Inability to distinguish between what is and isn’t desirable
Side effects of ecstasy
Nausea and dry mouth
Increased blood pressure and temperature
Large doses can cause anxiety and panic
Drug induced psychosis
Most commonly used illicit drug is cannabis
What is the psychoactive agent in cannabis?
Tetrahydrocannabinol (THC)
Symptoms/psychological effects (5) of cannabis
Relaxing or stimulating
Increases sociability and hilarity,
Increases appetite,
Changes in time perception, Synaesthesia (neurological trait/condition that results in a merging of senses that aren’t normally connected, e.g. hearing colour)
In higher dose - anxiety, panic, hallucinations
Ill effects of cannabis
Resp depression
Toxic confusion (delirium)
Exacerbation of existing major mental illness
Novel psychoactive substances also known as
legal highs
Anabolic steroids are a family of drugs comprising analogues of what hormone usually
Testosterone
Anabolic steroids are often abused by athletes (to increase muscle mass + reduce fat) but they can be clinically prescribed for what conditions
Hypogonadism
Muscular dystrophy
Various anaemias
Side effects of steroids
- skin
- males
- females
- cardio
- bone
- liver
Skin - stretch marks, acne, baldness
Feminisation in males with hypogonadism and gynaecomastia
Virilisation (masculinisation) in women, e.g. hirsutism, deep voice, clitoral enlargement
Cardio - increased cholesterol, hypertension
Bone - growth deficits due to premature closure of epiphyses
Liver - cholestatic jaundice, liver tumours
Psychological side effects of anabolic steroids
Irritability and anger
Hypomania or mania
Depression and suicidality on withdrawal
