Alcohol Flashcards
How do you calculate grams of alcohol per 100mls?
%ABV x 0.78
How many grams of absolute alcohol are in 1 unit?
8
What is the number of units of alcohol consumed per week that is considered safe?
Fewer than 14
How is binge-drinking defined?
> 8 units in one sitting
Why does alcohol have a much less profound acute effect when drunk on a full stomach?
Alcohol is mostly absorbed in the small intestine
Full stomach slows gastric emptying, so alcohol reaches blood stream more slowly
Why is the breath test effective to show alcohol levels?
10% of alcohol is excreted unchanged via the lungs
What enzymes are required for the first metabolic reaction of alcohol, and what does this produce?
Alcohol dehydrogenase
CYP450
–> acetaldehyde (very toxic)
Recall the metabolism of aldehyde
Liver: aldehyde dehydrogenase breaks it down to acetic acid
What is the cause of Asian flush?
Genetic polymorphism of aldehyde dehydrogenase
What is the use and mechanism of action of the drug disulfuram?
Use: alcohol-aversion therapy
MOA: blocks acetaldehyde dehydrogenase to induce severe nausea
By what mechanism is tolerance to alcohol developed?
UPregulation of mixed function oxidase (CYP450) in liver
Other than body mass, why do females tend to have a lower alcohol tolerance than men?
- Have a lower concentration of alcohol dehydrogenase in stomach
- HIgher % body fat
Recall the 3 biochemical targets of alcohol that produce the acute physiological effects
- GABA receptors
- NMDA receptors
- Calcium channels
How does alcohol affect GABA receptors?
Positive effect (unknown mechanism)
How does alcohol affect NMDA receptors?
These receptors are excitatory - alcohol decreases activation
How does alcohol affect calcium channels?
Reduces opening –> negative effect on NT release generally
Describe the potency of ethanol
LOW - due to molecular simplicity
What is the main effect of alcohol on the CNS
Depressant
Recall 6 regions of the brain that are acutely affected by alcohol intake
- Corpus callosum
- Hypothalamus
- RAS
- Hippocampus
- Cerebellum
- basal ganglia
Other than the CNS, where else does alcohol have acute effects?
CVS
Endocrine system
Describe the acute effects of alcohol on the CVS
- Tachycardia (depressant effect on baroreceptors)
2. Cutaneous vasodilation (asian flush - caused by acetaldehyde)
Describe the acute effects of alcohol on the endocrine system
Diuresis - as VP production is increased
What is the main cause of complications of chronic alcohol use on the brain?
Thiamine deficiency
