Psychostimulants BASICS Flashcards
general drugs for ADHD
- Amphetamines/Amphetamine-like agents (methylphenidate) (IR or XR)
- Atomoxetine (NSRI)
- Guanfacine and Clonidine (alpha-2 agonists)
amphetamines MOA
(ADHD)
Stimulate monoamine neurotransmitters (promote release of biogenic amines from storage sites)
Prevents storage of dopamine in vesicles in the axon terminal.
High levels of dopamine.
Transporters push domamine into synaptic cleft due to high concentration.
Why are there cardiovascular concerns with amphetamines?
(ADHD)
Stimulants –> stimulate NE release.
NE most readily stimulates Alpha-1 receptors –> increased vasoconstriction, increased peripheral resistance –> increased blood pressure
atomoxetine (strattera) use and MOA
ADHD
Selective inhibitor of NE transport (NSRI)
NONSTIMULANT
Blocks NE reuptake so it is available in synapse for longer.
Guanfacine, Clonidine use/MOA
ADHD
MOA: alpha-2 receptor agonists –> prevents release of NTs (MOA for ADHD unclear)
drugs for treatment of sleepiness, narcolepsy, cataplexy
Caffeine
Modafinil
Gammahydroxybutyrate
caffeine is an analog to ________
caffeine is an analog to ADENOSINE
caffeine mechanism
(sleepiness)
MOA: adenosine receptor antagonist (same shape, but does not cause same effect, just blocks site)
Adenosine binding to PRESYNAPTIC receptor:
- closes Ca++ channels
- decreased NT release
Adenosine binding to POSTSYNAPTIC receptor:
- open K+ channel
- hyperpolarizes cell
- decreased response to stimuli
If BLOCKED:
- increased NT release
- increased response to stimuli
mechanism of Modafinil (provigil)
Blocks dopamine transporter (dopamine available in synapse longer).
Increases synaptic dopamine (DSRI).
Not entirely clear how it relates to sleep
Modafinil uses
Excessive sleepiness.
- narcolepsy
- shift work
- obstructive sleep apnea
use of GHB (gammahydroxybutyrate)
Cataplexy (low muscle tone –> falls).
Narcolepsy.
Promotes profound sleep at night, so less likely to fall asleep the next day.
MOA of gammahydroxybutyrate (GHB)
(narcolepsy, cataplexy)
- potent enhancer of GABA (powerful sedative)
- exhibits GABA and dopamine-like effects
date rape drug (conscious sedation)
names/types of anorexiants
- phentermine: NE transporter inhibition
- lorcaserin: 5HT(2C) receptor agonist
- bupropion + naltrexone: DA and NE reuptake inhibitor and opioid receptor antagonist
anorexiants are used to
Treat obesity.
Moderate weight gain.
Have rebound effect when stop using so beware.
phentermine (lonamin) MOA
anorexiant
NE transporter inhibition
- NE stays in synapse longer, acts as stimulant
- sympathetic NS activated, parasympathetic suppressed
