Alcohol Flashcards
Where is alcohol excreted?
10% excreted by lungs and urine
90% oxidised in lover by alcohol dehydrogenase and microsomal ethanol oxidation system
Describe the distribution of alcohol
Distributes to all aqueous spaces
Absorption is slowed by food
Women exhibit higher peak blood alcohol conc than men
As they have lower body water and lower gastric alcohol metabolism
Metabolism of alcohol at low concentration
Alcohol to acetaldehyde by alcohol dehydrogenase
(This also converts nad+ to nadh)
Acetaldehyde to acetate by aldehyde dehydrogenase
(Nad+ to nadh)
What is alcohol dehydrogenase and where is it found?
Cytosolic zinc containing protein found in lover and brain
Alcohol metabolism at high concentrations
Microsomal ethanol oxidising system (induced by chronic alcohol consumption)
Converts nadp+ to nadph
And alcohol to acetaldehyde
Acetaldehyde to acetate by aldehdye dehydrogenase
And nad+ to nadh
What does acetaldehyde cause?
Nausea, facial flusing, dizziness and headache
What does disulfiram cause?
Which also happens in some asians.
Inhibits aldehyde dehydrogenase
Therefore more acetaldehyde accumulates
Disulfiram was used for drug additcs, but didnt work.
What does excess nadh cause?
Alters liver function probably in the basis of liver toxicity
What is foetal alcohol syndrome
The foetus cannot metabolise alcohol
Mothers who drink alcohol leads to loss of neurones in animal models
Characteristic facial abnormalies (train track ears, folds on inside of eye, smooth philtrum
There is no safe level
How does ethanol make you drunk?
Not sure? Drug is weak and dirty No specific receptor identified Delta subunit of gaba r Inhibition of nmda r Inhibition of n type calcium channels
Main response is inhibition a depressant
Also causes endogenous opiate release, activation of mu and delta opiod receptors
What are the mechanisms underlying chronic tolerance?
Increase in number and activity of enzymes that metabolise ethanol
Long lasting changes in the abundance and function of receptors
Mechanisms of acute alcohol tolerance?
Changes in function of nmda and gaba r
Nystagmus
What is himmelsbach hypothesis?
Withdrawl is what happens when alcohol mediated adaptions function in absence of alcohol
Ie. symptoms of withdrawl are opposite to effects of drug
Symptoms of withdrawl?
Arises due to abrupt cessation after chronic use
Motor agitation, anxiety, insomnia and reduction in seizure threshold
Delirium tremens (hallucinations, tremor, hyperpyrexia, sympathetic hyperactivity, death)
Treatment for withdrawl?
Hair of the dog? Works due to himmelsbach hypothesis
Benzodiazepines most commonly used in rehab to detox, but v dangerous if taken with alcohol
