Svensson Lectures Flashcards
Psychostimulants use & effects
- activate CNS resulting in alertness, excitation, and elevated mood
- stimulants play a major role in drug abuse crisis
Stimulants historical & medical use
- Cocaine: reduce hunger & fatigue; anesthetic
- ephedrine widely used for asthma & overall stimulant properties
- nicotine smoking to treat asthma
- amphetamines for various uses
Nicotine - MOA
- activates nicotinic acetylcholinergic receptor
- Na enters cell, K exits, which creates an action potential.
- heterogeneity of subunits determines how many molecules of Ach bind to receptor
- variation in receptor composition at different sites may influence physiological response
ACh vs Nicotine
- both have charged amino groups and H bond acceptor groups
- nicotine is membrane penetrable at physiological pH
- nicotine is not degraded by acetylcholinesterase
partial agonist therapy
- causes release of dopamine
- highly addictive
- nicotine replacement therapy relatively ineffective alone
- varenicline partial agonist increases quit rate success
Cocaine MOA
- antagonist of amine transporters: DAT, SERT, NET
- DAT>= SERT > NET
- prevents DA reuptake and increases DA concentration
- also increases duration of dopamine action
Methamphetamine, Ecstasy, & Bath Salts – MOA
- amphetamines/XTC/bath salts compete for reuptake (resemble endogenous DA, NE; they block DA reuptake and push out DA from vesicles)
- increase extra-vesicular DA, reverse transport gradient
- amphetamines are MAOi’s
- activate Trace amine-associated receptor (TAAR1) which phosphorylates DAT and induces reverse transport function
Mesolimbic Dopamine System
key dopaminergic pathway that transports dopamine from the ventral tegmental area to the nucleus accumbens and amygdala
addiction liability
- likelihood that a person using the drug will become addicted
sympathomimetic toxidrome
a constellation of signs/symptoms indicative of ingestion of psychostimulant
cocaine
a psychostimulant first isolated from cocoa leaves in 1857. primarily an inhibitor of dopamine transporter, preventing reuptake of DA released into synaptic cleft
Nicotine
most addictive substance in current use; activates nicotinic acetylcholinergic receptors
- (other psychostimulants directly enhance dopamine release and inhibit reuptake)
methamphetamine, ecstacy, MDMA
psychostimulants that primarily release endogenous DA
cathinones
derivatives of Khat plant (bath salts) that display similat activity to methamphetamine
dose-effect of psychostimulants
low dose - enhance wakefulness and vigilance
higher doses - increase agression, euphoria, and psychosis
chronic psychostimulant use effects
- produce tremors, anxiety, paranoia, delusions, repetitive behavior, profuse dental decay, dilated cardiomyopathy
- results in downregulation of DA receptors (return to baseline after period of abstinence)
Hallmarks of Sympathomimetic Syndrome
MATHS:
- mydriasis
- aggitation/arrhythmia/angina
- tachycardia
- hypertension/hyperthermia
- seizures/sweating
Hemp
a strain of cannabis that is grown for agricultural products and contains less than 0.3% THC
Marijuana
a strain of cannabis sativa that commonly contains 15-20% THC content for its psychoactive effects
Synthetic Marijuana
Illicit synthetic compounds that are analogs of THC and bind to CB1 receptor as full agonists producing similar psychoactive effects as THC
Endocannabinoid System
an endogenous system comprised of four components
1 cannabinoid receptors
2 ligands
3 endocannabinoid membrane transporters
4 synthetic and degradative enzymes
this system regulates immunity, memory, mood, pain, and perception
THC
tetrahydrocannabinol is the primary euphoric component in marijuana is an agonist of CB1 and CB2 receptors of ECS
CBD
cannabidoil is a non-euphoric natural cannabinoid widely marketed for variety of uses that is not an agonist for CB receptors
Δ8-THC:
A euphoric componene in cannabis sativa that is increasingly present in the unregulated market
