Drug misuse and addiction Flashcards
what are the two mechanisms are responsible for addiction of a drug?
dependence due to tolerance of the drug
psychological craving due to activation of the reward centre
describe the pathway of the reward centre.
neurones pass from the ventral tegmental area to the nucleus accumbens to the pre-frontal cortex
what are the mechanisms of tolerance?
less drug reaching active site;
- increased metabolism of drug
- increased excretion of drug
- less drug absorbed
drug has less action at the active site
- fewer receptors
- less efficient drug receptors
how does heroin, cocaine and amphetamines impact the reward centre and why does this impact addiction?
activation of the reward centre leads to cravings
heroin increases firing of dopaminergic neurones
cocaine decreases uptake of dopamine
amphetamines increase the release of dopamine
what symptoms may someone experience from withdrawal from cocaine?
depression irritability agitation craving hyper somnolence hyperphagia
what symptoms may someone experience from withdrawal from opiates?
diarrhoea muscle pain and cramps craving nausea insomnia dilated pupils piloerection increase in salivary and lacrimal secretions
what are the effects from opiates such as heroin?
euphoria
analgesia
drowsiness / sleep
what are the positive effects from cocaine?
euphoria alertness lack of judgement energy decrease need for food and sleep
what are the negative consequences from cocaine?
potent vasoconstrictor - ENT problems paranoid psychosis toxic confusion seizures respiratory failure hypertension stroke (cerebrovascular accident) arrhythmias
what are the negative consequences from heroin?
decreased sympathetic outflow - hypotension, bradycardia
hypothermia
respiratory depression
cough reflex depression
constipation
sensitisation of the labyrinth with nausea and vomiting
what’s the difference between the effects of amphetamines and cocaine?
amphetamines have the same effects as cocaine but last longer
what are the main negative consequences of heavy amphetamine use?
toxic confusion with convulsions
amphetamine psychosis
what are the methods of use of heroin?
smoking
injecting
snorting
what are the methods of use of cocaine hydrochloride and crack cocaine?
crack - smoked
cocaine powder - snorted
coca leaves - chewed or brewed
what are the features of opiate overdose?
respiratory arrest with a pulse
pin point pupils - fixed and unreactive to light
snoring giving way to shallow respiration (< 8 breaths/min)
bradycardia and hypotension
reduced consciousness / coma
what are the side effects of opiates?
first time - nausea and vomiting
medium term - phlebitis, anorexia, constipation
long term - tolerance, withdrawal, social and health problems
what are the effects of ecstasy (MDMA)
euphoria followed by feeling of calm
increased sociability
inability to distinguish what is and isn’t desirable
what are the side effects of ecstasy (MDMA)?
nausea dry mouth increased blood pressure and temperature anxiety and panic (high doses) drug induced psychosis dehydration risk if taken in a club
what are the effects of cannabis?
relaxing or stimulating euphoriant increases appetite prolonged use it can change perception and cause synaesthesia increases sociability and hilarity
high doses:
- anxiety
- panic
- persecutory ideation
- hallucinatory activity
what are the negative consequences of cannabis?
respiratory problems
toxic confusion
exacerbation of major mental illness
psychosis
what are the physical side effects from steroids?
acne
hirutism
scalp hair loss
growth deficits (premature closing of epiphysis)
hypogonadism and gynaecomastia in males
deep voices, clitoral enlargement and menstrual irregularity in women
increased cholesterol and hypertension
cholestatic jaundice and liver tumours
what are the psychological side effects from steroids?
rage and irritability
hypomania and mani
depression and suicidality on withdrawal
what are the 3 main drugs that cause the greatest psychological withdrawal symptoms?
opioides
cocaine
tobacco
what are the 3 main drugs that cause the greatest physical withdrawal symptoms?
opioids
barbiturates
alcohol
what is the definition of tolerance?
a state in which a person functions normally only in the presence of a drug
manifested as a physical disturbance when the drug is removed = withdrawal symptoms
how might substance dependance present in the general hospital?
forged pain in order to received drugs withdrawal overdose trauma / accident drug induced psychosis physical complications alcohol related brain damage
