Lecture 11: Psychostimulants Flashcards
3 therapeutic effects of psychostimulants
- local anesthetic
- ADHD treatment
- narcolepsy
how do stimulants exert their behavioral effect? where?
augmenting DA action
activity in NA
low dose effects of PS induce ___
behavior-activating response akin to normal emergency reaction (sympathomimetic drugs)
3 physiological effects of sympathomimetic drugs
- increased BP and HR
- blood flow shifts from skin and organs to muscles
- oxygen and blood glucose levels rise
4 positive CNS effects of PS
- elevated mood
- reduced fatigue/increased energy
- decreased appetite
- improved task performance
3 negative effects of PS
anxiety
irritability
insomnia
3 high dose negative effects of PS
anxiety
irritability
psychotic behavior
PS used historically for 5 reasons
- endurance
- sense of wellbeing
- reduce fatigue
- increased stamina
- alleviate hunger
cocaine is the ___ most popular illegal drug in US
2nd
estimated cocaine market in US exceeds ____
$70 billion
Harrison Narcotic Act
1914; banned incorporation of cocaine into medicines and beverages
cocaine related ER visits were second only to ___
illicit drug use combined with alcohol
3 types of cocaine
E. coca leaves
Cocaine HCl
Cocaine base (crack, freebase)
crack is soluble in (3)
alcohol
acetone
ether
% cocaine in coca paste
60-80%
% cocaine in E. coca leaves
1%
how many mgs of cocaine per line?
25mg; snort 50-100mg at a time
how much of cocaine HCl is absorbed through snorting? what inhibits it?
20-30%
cocaine is a vasoconstrictor
plasma level peak of cocaine
30-60 min
how long does cocaine persist in plasma?
6 hours
for smoked cocaine freebase, absoprtion is ___
rapid and complete
onset and persistance of smoked freebase
5 min; 30 min
onset of IV powder cocaine
30-60s
cocaine metabolite. how long can it be detected in urine?
benzoylecgonine
detected in urine 48h after use; 2 weeks in chronic users
when combined with alcohol, cocaine is metabolized to…
cocaethylene
effects of cocaethylene (3)
- can be more active/longer lasting than cocaine
- blocks DA reuptake transporter
- increases risk of toxicity
cocaine MoA
potentiates actions of DA and 5HT by blocking active reuptake
mice lacking ___ do not self administer cocaine
dopamine reuptake transporter
8 low-dose cocaine effects
- alertness
- motor hyperactivity
- tachycardia
- vasoconstriction
- hypertension
- bronchodilation
- increased blood glucose levels
- blood flow shift to muscles
cocaine psychological response first 30 min
- euphoria
2. enhanced self-consciousness and boastfulness
cocaine psych response next 60-90 min
mild euphoria mixed with protracted anxiety
8 risks/complications of acute cocaine use
- racing thoughts/speech
- depression
- suppressed appetite
- delayed sleep
- movement disorders
- seizures
- depletion of oxygen (cerebral ischemia)
- intracranial hemorrhage
toxic paranoid psychosis (4)
- anxiety
- sleep deprivation
- repetitive compulsive behavior
- altered perception of reality, violent responses to imagined persecution
cocaine psychosis (8)
- paranoia
- impaired reality testing
- stereotyped, compulsive, repetitive behavior
- vivid hallucinations
- irritability
- extreme psychomotor activation
- impaired relationships
- disturbances in eating and sleeping
how old do cocaine dependent people tend to be?
12-39 years
cocaine users are usually dependent on at least ___ drugs
3
___ of cocaine users are male
75%
on personality tests, cocaine users tend to be (4)
reckless
rebellious
low tolerance for frustration
craving for excitement
___ of cocaine users have anxiety disorders
30%
___ of cocaine users are clinically depressed
67%
___ of cocaine users exhibit paranoia
25%
cocaines vasoconstrictive effects can cause what in the fetus? (3)
- increased blood pressure
- intracerebral hemorrhage
- premature birth
fetus exposure to cocaine can lead to (2) later in life
- behavioral/emotional problems
2. increased vulnerability to substance use in adolescence
when cocaine crosses the placental barriers, can lead to (2)
- destructive brain lesions
2. sudden infant death syndrome
effects of cocaine neurotoxicity (3)
- psychomotor slowing and slowed reactions
- subclinical brain damage; early onset demention
- upregulation of heat shock protein expression, causes damage in BBB
3 pharmacological strategies in cocaine dependency
- block euphoria
- reduce withdrawal/depressive symptoms
- enhance PFC cortical projections
compounds that regulate ____ are in early clinical trial for cocaine dependency (2 examples)
glu transmissions from frontal cortex to VTA and NA
topiramate and lamotrigine
7 drugs for cocaine dependency
- disulfiram (antabuse, blocks aldehyde dehydrogenase)
- naloxone (opiate antag)
- methylphenidate
- wellbutrin
- modafinil
- antidepressants (not SSRIs)
- antiepileptic neuromodulators (increase GABA by inhibiting GABA transminase enzyme; attenuates DA levels in NA and reduces cravings)
3 problems with cocaine vaccine
- need enough antibodies to bind to all bloodstream cocaine
- long lasting needed to reduce number of readministrations
- vaccine should be well tolerated
only ___ of those vaccinated for cocaine attained high enough antibody levels
38%
MoA of amphetamine (3)
- DA and NE release from presynaptic nerve terminals
2. amphet causes transporters to run in reverse, leading to release of vesicular DA into cytoplasm and synaptic cleft
what causes stereotypical, repetitive, compulsive behavior from amphetamines?
increased DA in basal ganglia
4 low dose effects of amphet
- increased BP and HR
- increased alertness, euphoria, excitement, wakefulness
- loss of appetite
- improved task performance
4 moderate dose effects of amphet (not BP/HR, alertness/euphoria, appetite loss, task perform)
- tremors/restlessness
- worsening production of anxiety disorders/panic disorders/obsessive behavior
- paranoid psychosis
- insomnia
6 chronic use, high dose effects of amphet (not anxiety, insomnia, tremors)
- stereotypical behaviors
- sudden violent outbursts
- paranoid delusions
- severe anorexia/weight loss
- skin sores from neglected healthcare
- indirect negative fx by poor eating and sleeping
2 withdrawal symptoms of amphet?
- increased appetite/weight gain
2. severe depression
methamphetamine can be easily synthesized from obtainable chemicals like ___
pseudoephedrine
ice
crystalline, smokable form of meth (like crack)
half life of meth
12 hours
2 high dose effects of meth
violent behavior
paranoid/psychotic behavior
2 effects of meth repeated dosing
- long lasting decrease in DA and 5HT in brain from damage to 5HT and DA nerve terminals
- neuronal death; replacement with astroglia and microglia
chronic meth use has what 4 effects on the brain?
- reduces hippocampal volume
- increases size of ventricles
- decreases gray matter
- increases white matter
how does meth cause BBB breakdown? what are the effects?
causes hyperthermia
increases numbers of WBCs in brain, initiating neuronal damage
6 nonamphet behavioral stimulants
- ephedrine
- pseudophedrine
- ritalin
- provigil (modafinil)
- nuvigil (armodafinil)
- kat
use of ephedrine
anesthesiology to increase BP
releases epinephrine, elevating BP and heart rate
use of pseudoephedrine
used to relieve nasal congestion
2 actions of ritalin
- blocks presynaptic DA transporter
2. slightly increases DA release
after 60 min of oral admin, ritalin effect is ___
blocks 50% of DA transporters
what accounts for low rate of positive reinforcement from ritalin?
slow uptake into brain
modafinil MoA (2)
- blocks dopamine transporter
2. elevation of hypothalamic histamine levels
3 FDA approved uses of modafinil
- narcolepsy
- shift-work sleep disorder
- obstructive sleep apnea
khat; how is it consumed?
east african flowering shrub
can be chewed or brewed as tea
3 effects of khat
- excitement
- loss of appetite
- euphoria
active ingredients in khat
- cathinone
2. cathine
what does cathinone do?
increases DA levels in CNS
what does cathine do?
mild psychostimulant
differences in cocaine vs. amphetaine action
- cocaine: potentiates action of DA and sereotonin by blocking active reuptake
- amphetamine: causes release of DA from vesicles and cause DAT to run in reverse
effects of meth related 5HT damage (3)
- anxiety
- depression
- aggression
DA damage from meth use makes users vulnerable to ___
neurodegenerative disorders like parkinson’s
what 3 parts of the brain are most damaged by meth BBB breakdown?
most severe in
- amygdala,
- hippocampus, and
- caudate-putamen
where does cocaine increase DA activity?
nucleus accumbens
where does amphetamine increase DA activity?
nucleus accumbens
meth MoA (2)
- release of DA from vesicles
2. causes DAT to run in reverse