Addictions symposium Flashcards
Tolerance and reward centre responsible for
tolerance - physical dependence
reward centre - psychological craving
Tolerance
reduced responsiveness to a drug caused by previous administration
Which rugs show tolerance?
BZD, opiates, alcohol, barbiturates
dispositional tolerance
less drug reaching active site
increased metabolism and excretion
decreased rate of absorption
pharmacological tolerance
site of action less effected by drug
internalisation or down regulation of receptors
Why may tolerance lead to withdrawal symptoms?
avoid negative side effects
Are the withdrawal symptoms the same or opposite as the effect of the drug?
opposite
opioid, barbiturate and cocaine - effect and withdrawal effect
constipation - diarrhoea
anti convulsant - convulsions
increase mood - decrease mood
Reward pathway
neurons from VTA - nucleus accumbens - prefrontal cortex
What happens when VTA neurons stimulated?
dopamine release
Dopamine action
pleasure and reward eg food, sex
Examples of drugs tapping into reward system
alcohol, heroin, amphetamine, cocaine
2 stimulants
cocaine and amphetamine
Early use of cocaine
coca leaves in 1880 - ENT surgery
Ingesting cocaine
leaves chewed, cocaine HCL snorted or injected and crack cocaine smoked
Effect of cocaine depends on?
dose and rate of entry to brain
Rate of entry to brain of cocaine depending on how it is taken
smoking - immediate
inject is 15-30s
snort - 3-5mins
cocaine effects
convulsions with resp failure damage to nose and airways toxic confusions hypertension and CVA cardiac arrhythmias and MI paranoid psychosis less appetite and desire for sleep increased confidence and impaired judgement increased alertness and energy stimulant and euphoriant
cocaine withdrawal effects
depression hyperphagia hypersomnia irritability agitation craving
Amphetamine
amphetamine sulphate - sniffed, swallowed, inject
Effects of amphetamine
similar to cocaine but longer lasting
toxic confusion occasionally with convulsions and death
psychosis
Examples of opiates
opium, morphine, heroin, methadone, codeine
Heroin effects
analgesia, sleep, euphoria, resp depression, bradycardia, constipation, pinpoint pupils, “rush”
side effects of heroin
first time - N&V, headache
medium - phlebitis, anorexia and constipation
long term - tolerance, withdrawal, social and health problems
opiate withdrawal
craving, yawning, insomnia, muscle pain, dilated pupils, piloerection
Positives of methadone maintenance
decriminalises drug use, reduces IV misuse
normalise life
Ecstasy effects
increased talkability, euphoria then calm, 2-4 hours
side effects of ecstasy
nausea - dry mouth - dehydration - panic - anxiety - hallucinations - psychosis - increase blood pressure - brain and liver
Components of cannabis
THC is psychoactive
cannabinoids in CBD
Effects of cannabis
relaxing or stimulating euphoriant increase sociability and hilarity increase appetite high dose - anxiety, hallucinations synaesthesia
ill effects of cannabis
respiratory, toxic confusion, mental illness, psychosis
What are novel psychoactive substances?
legal highs
Anabolic steroids prescribed in
muscular dystrophy, wasting in AIDS
Muscle hypertrophy areas with anabolic steroids
deltoid, pectoralis, trapezius, biceps
side effects of anabolic steroids
acne, stretch marks, bald feminisation in males and virilisation in females increase cholesterol and HTN premature closure of epiphysis liver disease
psychological effects of anabolic steroids
roid rage - irritable and anger
hypomania and mania
depression and suicidal on withdrawal
