Ethanol Flashcards
the drug action of ethanol (40 cards)
How does Ethanol affect the CNS?
It is a depressant of the CNS
What happens as the dose of ethanol increases?
As increase dose:
o Relief from anxiety
o Disinhibition
o Sedation
o Hypnosis (sleep)
o General anesthesia
o Coma
o Death
CNS depressants have additives effects, meaning?
Their effects add up
a. Sedatives, antidepressants, anticoagulants, antianxiety, opioids
b. Take sleeping pill after a lot of drinks, additive effects, never wake up
Can the effects of ethanol be reversed by a CNS stimulant?
No, coffee will not fix the problem
CNS Depressants will have a rebound excitation when stop taking it?
Take alcohol every day, stop drinking, rebound excitation that can be very serious
What are the consequences of cross tolerance of CNS depressants?
a. Need to keep taking more of them to get the same effect
b. Frequent drinkers go to the hospital and are given another drug at higher dose because of cross tolerance
Alcohol effects your? (3 things)
Emotions
Judgement
Voluntary motor skills
What are two types of amnesia possible when drinking alcohol?
Partial amnesia, blackouts
What is partial amnesia?
Partial amnesia: fragmental loss of memory, person later unaware of memory gaps, universal, dose related
What are blackouts?
Blackouts: total loss of memory for specific time, person later aware of 0 memory, susceptibility varies, not everybody has this, don’t have to be at a high level
What pathways does ethanol act on?
Acts on:
- Vision
- Sensation
- Movement
- Coordination
- Memory
- Judgement
- Reward (addiction) increase dopamine
What type of ion channel is the GABA A receptor?
A ligand gated ion channel for chlorine.
How does ethanol act to depress the CNS?
Ethanol acts presynaptically on GABA receptors that release GABA to activate the postsynaptic GABA receptors allowing Chlorine (Cl) to flow in causing inhibition of the CNS. (ethanol increases GABA inhibition)
Ethanol also releases Glycine, another inhibitory pathway
Ethanol effects the inhibitory pathway and the excitatory pathways?
Ethanol blocks glutamate transmission:
Impair intellectual function
Increased inhibition (GABA)
Decreased excitation (NMDA receptor for glutamate)
Inhibits excitation: glutamate receptors
Potentiates inhibition: GABA and Glycine receptors
How does alcohol withdrawal cause excitation?
When you chronically block glutamate receptors, they are upregulated, alcohol withdrawal risk of convulsions
What neurotransmitter concentrations does ethanol effect?
Lowers release of Acetylcholine, serotonin
Facilitates release of dopamine, opiate neuropeptides
Blocks voltage gated Ca channels
aggression serotonin neurotransmission
Decrease: impulsiveness
Ethanol blocks Ach release: amnesia, cognitive impairment
In reward pathway lowers GABA inhibition, more dopamine release
Is ethanol well absorbed?
Yes, its highly lipid soluble
How fast does ethanol onset? When is the peak effect?
Rapid, detect in 5 minutes in blood, peak at 30-90 minutes
- Rate of absorption increased by carbonation goes into small intestine faster absorbs very well in intestine, decreased by food, fat
Where is ethanol absorbed?
stomach, small intestine
- About 20% absorbed in stomach, high level of ADH in gastric mucosa, side effect gastritis
- Rate of absorption is much greater on an empty stomach because it will get to the small intestine faster
Apparent volume of distribution ethanol =?
total body water
- Males have more total body water, so women will have a higher percentage of alcohol since their total body water is less
Is ethanol well distributed?
Yes, ethanol is a small molecule, it can pass through cell membranes easily
Apparent volume of distribution (AVD)
Amount of drug in the body / concentration of drug in circulation
Ethanol has a high AVD
therefore, most is bound to tissues
Does ethanol get to the brain fast?
yes, High blood flow to the brain, ethanol enters rapidly, ethanol can just dissolve in the membranes to get to the brain
Does Ethanol stimulate the CTZ?
yes, it makes you vomit as a protection mechanism
