Ch6: Alcohol

Question 1

How is blood alcohol content expressed?

Answer 1

Milligrams (mg) of alcohol per 100 millilitres (ml) of blood.

E.g., BAC of 80 mg of alcohol per 100 ml of blood (80 mg/dl) is equivalent to 0.08%

Question 2

Alcohol dehydrogenase

Answer 2

Main enzyme that breaks down alcohol.

Alcohol breakdown is in the stomach, where first-pass metabolism occurs, catalyzed by alcohol dehydrogenase.

Question 3

What is the route of metabolism for alcohol?

Answer 3

Two steps:

1) Rate-limiting step
- Alcohol is converted to acetaldehyde by alcohol dehydrogenase enzyme
- Slowest step in alcohol metabolism
- Rate of conversion depends on amount of alcohol dehydrogenase available
- Independent of concentration of alcohol

2) Acetaldehyde is converted into acetyl coenzyme A
- Converted by several enzymes, most common is aldehyde dehydrogenase
- In citric acid cycle, acetyl coenzyme A is converted into water and CO2

Question 4

What are two stages of alcohol withdrawal?

Answer 4

1) Early minor syndrome
- 8-12 hours after drinking
- Agitation, muscle cramps, nausea, sweating, irregular heartbeat
- Over within 48 hours

2) Late major syndrome
- After 2 days of minor symptoms
- Increasing agitation, disorientation, confusion, hallucinations
- Last 7-10 days

Question 5

What factors are associated with the likelihood of fetal alcohol syndrome (FAS) or fetal alcohol effects (FAE)?

Answer 5

• Alcohol during pregnancy is necessary but not sufficient
• Having previous children
• Being black
• Having a high score on an alcohol screening test
• Having a high %age of drinking days
• Occasional high levels of consumption do more damage than the same amount of alcohol consumed at chronic low levels

Question 6

What do benzodiazepines do to GABA receptor opening?

Answer 6

Benzodiazepines increase frequency of GAPA receptor opening

Question 7

What do barbituates do to GABA receptor opening?

Answer 7

Barbiturates increase duration of GABA receptor opening

Question 8

What does ethanol do to GABA receptor opening?

Answer 8

Ethanol increases frequency and duration of GABA receptor opening

Question 9

What are individual differences in the effect of ethanol on the body?

Answer 9

• Gender
• Speed of gastric emptying
• Levels of metabolic enzymes
• Genetics
• Age
• History of drinking