amphetamines Flashcards
background and history, neural mechanisms, chronic vs recreational use, clinical applications, treatment strategies (36 cards)
what are amphetamines?
synthetic psychostimulant
in terms of chemical structure is similar in nature to neurotransmitter dopamine
increase energy, euphoria, alertness
has severe hallucinogenic properties
what are examples of amphetamines?
MDMA
meth
speed
ecstasy
Molly
where can you get amphetamines?
amphetamines for medicinal purposes are regularly prescribed by doctors for a range of medical conditions
similar chemical compounds that are naturally occurring (Ephedra) have been consumed for more than 5000 years across north America, southern Europe, northern Africa, southwest and central Asia, northern China and western South America
what are the origins and consumptions?
Ephedra now banned appetite suppressant
in 1920s, ephedrine used for asthma
led to search for synthetic substitute - amphetamine inhalar
later marketed for narcolepsy
pseudoephedrine still used as bronchodilator
Obetrol was a popular diet pill in Amiercan in the 1950s and 60s
used in WW2
what are the methods of ingestion?
recreational drugs (meth/speed) are taken orally and takes up to 30 minutes for effects to occur
due to half-life of the drug (7-30 hours) users typically experience a longer high then users of drug such as cocaine
typically taken orally as a tablet but it can be crushed and then snorted or dissolved in water than injected
what are the effects?
has many medicinal properties and is used to treat a range of psychological conditions
as a recreational drug, it is taken to give a sense of euphoria, alertness and to increase energy
what are the mild to moderate effects?
mood amplification - both euphoria and dysphoria
heightened energy
sleep disturbance, insomnia
motor excitement, restlessness
talkativeness, pressure of speech
hyperactive ideation
increased sexual interest
anger, verbal aggression
mild to moderate anorexia
inflated self-esteem
what are the severe effects?
irritability, hostility, anxiety, fear, withdrawal
extreme energy or exhaustion
total insomnia
compulsive motor stereotypies
rambling, incoherent speech
disjointed flight of ideas
decreased sexual interest
possible extreme violence
total anorexia
delusions of grandiosity
what are the neural mechanisms of amphetamine action?
inhibits transporter to increase synaptic levels (DA, NA, 5-HT) but also stimulates DA release
unlike cocaine which just blocks catecholamine reuptake (DA), amphetamines also actively release these neurotransmitters from nerve terminals
prevent reuptake of NA
AMPH taken up by DAT, inside terminally provokes DA release - plus DAT functions in reverse to further release DA
DA reuptake transporters are blocked by cocaine, resulting in increased DA in the synaptic cleft, leading to behavioural symptoms of cocaine use
what are the mechanisms of amphetamine action in animals?
if injected into nucleus accumben, high locomotor behaviour
injection in NAc leads to addiction
what is amphetamine psychosis?
Griffith et al (1972)
participants (n = 7) users but no prior history of psychosis
given 10mg dextroamphetamine every hour for up to 5 days
all became psychotic within 2-5 days
delusions mostly auditory, also included poisoning by experimenters and electric dynamo thought control
what are the behavioural effects of chronic amphetamine use?
addiction and dependence
cognitive impairment
mood disorders
psychosis
aggressive behaviour
sleep disturbances
what does it mean that chronic amphetamine use can lead to addiction and dependence?
long-term use often leads to physical and psychological dependence
users may feel unable to function without the drug and experience intense cravings
what does it mean that chronic amphetamine use can lead to cognitive impairment?
chronic use can impair cognitive functions like memory, attention and decision-making abilities
can affect daily activities and overall quality of life
what does it mean that chronic amphetamine use can lead to mood disorders?
associated with mood swings, irritability, anxiety and depression
mood disturbances can become more severe over time
what does it mean that chronic amphetamine use can lead to psychosis?
extended use can lead to amphetamine-induced psychosis
characterised by paranoia, hallucinations and delusions
condition can be similar to schizophrenia
requires medical intervention
what does it mean that chronic amphetamine use can lead to aggressive behaviour?
exhibit increased aggression and hostility
can strain relationships and lead to social isolation
what does it mean that chronic amphetamine use can lead to sleep disturbances?
long-term use disrupts normal sleep patterns
leading to insomnia and other sleep-related issues
what does it mean that chronic amphetamine use can lead to physical health decline?
chronic use can result in weight loss, malnutrition and cardiovascular problems, further affecting mental health and behaviour
what neurological effects does chronic amphetamine use lead to?
neurotransmitter imbalance
cognitive impairment
amphetamine-induced psychosis
neurotoxicity
structural brain changes
how does amphetamine use lead to neurotransmitter imbalance?
chronic use can disrupt regulation of DA, NA and 5-HT
leading to significant chemical imbalances and withdrawal symptoms
what does it mean that chronic amphetamine use leads to cognitive impairment?
long term use can impair memory, attention and decision-making abilities
affecting daily life and mental health
what does it mean that chronic amphetamine use can lead to amphetamine-induced psychosis?
prolonged use can result in paranoia, hallucinations and delusions
resembling symptoms of schizophrenia?
what does it mean that chronic amphetamine use can result in neurotoxicity?
extended use can cause nerve cell damage
increasing risk of seizures and strokes
