Alcohol

Question 0

What is the mechanism of action for alcohol?

Answer 0

Increase GABAa receptor activation
- hyperpolarisation of neurones by influx of chloride ions through the opening of chloride channels. This inhibits neural firing and consequently reduces the chance for an action potential to occur. More alcohol leads to further inhibition.
Decrease calcium entry through voltage gated calcium channels
-inhibits depolarisation and transmitter release
Decrease NMDA receptor function
- relieves NMDA receptor mediated tonic inhibition of dopamine releases in the nucleus accumbens. Activation of reward pathway.

Question 1

Where does dopamine project from and to where?

Answer 1

From VTA to limbic structures.

Question 2

What are the clinical features of alcohol withdrawal?

Answer 2

Psychomotor disturbance - tremor of hands and legs
Seizures - tonic clonic
Psychosis - hallucinations, paranoid
Delirium tremens - profound confusion, rapid heart rate, high blood pressure, dehydration, death

Question 3

What is wernicke-korsakoff syndrome?

Answer 3

Distinct brain lesions associated with irreversible and severe amnesia, ataxia and general confusion.
Associated with chronic neurological effects of alcohol consumption.
Caused by thiamine deficiency (vitamins B12) - cortical and sub cortical volume loss as well as direct toxic effects on CNS

Question 4

What are some chronic benefits of alcohol consumption?

Answer 4

Improved blood lipid profile - increase HDL and decrease LDL
Decrease thrombosis - reduce platelet aggregation, fibrinogen
Reduces blood pressure
Reduce blood insulin levels

Question 5

What is used to treat alcohol withdrawals?

Answer 5

Benzodiazepines
GABA agonists “-zepam”
Alleviates withdrawal symptoms such as cross tolerance with alcohol, anticonvulsant, anti anxiety.
Gradually withdrawn.

Question 6

What inhibits alcohol metabolism?

Answer 6

Disulfiram
Punishment based on pharmacotherapy, relapse prevention.
Inhibits aldehyde dehydrogenase - increases acetaldehyde
Cannot be used in ppl with liver problems.

Question 7

What is used to block acute positive effects of alcohol?

Answer 7

Naltrexone
Oral opioid antagonist.
Mechanism unclear possible indirect effects on dopamine.
Clinically used to reduce relapse and number of drinking days, reduces craving in some.

Question 8

What drug diminishes alcohol craving?

Answer 8

Acamprosate
NMDA antagonist and GABA agonist
Enhances abstinence