129 - Alcohol Metabolism Flashcards
Effect of ethanol on the brain
Disrupts lipid membranes in the brain.
This disrupts permeability of membrane.
Proportion of US population thought to be dependent on alcohol
~4%
Alcohol dependence definition by NHMRC
Severe Dependence exists when withdrawal causes tremors, anxiety, sweating
or vomiting.
Dependence is a continuum from mild to severe. It is more likely when family or
social groups exhibit high drinking patterns. People who cannot stop drinking,
when they realise that they should, are dependent
NH&MRC recommendations for alcohol dependence
The NH&MRC recommend complete abstinence from alcohol when dependence is evident.
Number of people with alcohol-related brain damage
~2 billion
Estimated cost of alcohol-related medical care, deaths, crime and lost productivity per year in Australia
~8 billion
Name for condition from alcohol neurotoxicity
Wernicke Korsakoff syndrome
Symptoms of Wernicke Korsakoff syndrome
Eyes uncoordinated (nystagmus), wide step, confusion, hypothermia, amnesia and confabulation.
Aetiology of Wernicke Korsakoff syndrome
Thiamine deficiency. Thiamine needed for energy supply of neurone.
Depleted through poor nutrition, alcohol metabolism destroys thiamine.
Proportion of alcohol metabolised in the liver
~90%
Signs of alcoholism 1 2 3 4 5 6 7 8 9 10 11 12
1) Neurological disturbances
2) Jaundice
3) Altered breath
4) Oesophageal varices
5) Feminisation (altered sex hormones)
6) Extensively-scarred live)
7) Portal hypertension
8) Ascites
9) Hand tremors
10) Hypogonadism
11) Easy bruisability
12) Oedema
Types of alcohol-induced liver damage
1
2
3
1) Fatty liver
2) Alcoholic hepatitis
3) Alcoholic cirrhosis
How does alcoholic hepatitis come about?
Damage of hepatocytes attracts immune system, causes inflammation.
Proportion of heavy drinkers with alcoholic hepatitis
Up to 50%
Mortality rate of alcoholic hepatitis
15-20%
Proportion of heavy drinkers with liver cirrhosis
15-30%
Proportion of hepatocytes required for normal liver functionality
At least 40%
Serum albumin concentration with liver damage
Remains quite normal until cirrhosis
Alcohol metabolism in the stomach
Alcohol dehydrogenase present in the stomach.
In caucasian males can metabolise ~1 standard drink
Proportion of alcohol absorbed in the intestine into the blood
~70%
Blood alcohol % at which brainstem stops working
~0.4%