Week 10 - Alcohol

Question 1

what is alcohol

Answer 1

• isopropyl
• methanol
• ethanol

Question 2

fermentation

Answer 2

• sugar dissolved in water
• yeasts multiply & convert sugar into ethanol & CO2
• alcohol content about 10-15%

Question 3

distillation process

Answer 3

• fermentation -> heated -> alcohol given off in vapour -> vapour cooled
• alcohol content ~ 40-50%

Question 4

measurement of alcohol

Answer 4

• BAL/BAC: concentration of alcohol in whole blood
• usually mg alcohol/100ml whole blood (or % of alchol in the blood
• SI units mmol/l

Question 5

administration method

Answer 5

generally oral

Question 6

can the molecules be ionized?

Answer 6

no therefore pH levels have no effect on absorption

Question 7

absorption

Answer 7

• readily dissolves in water & passes into blood from stomach lining, intestines & colon
• 1st pass metabolism - alcohol dehydrogenase in stomach

Question 8

what is absorption rate and blood alchol level affected by?

Answer 8

• stomach contents
• body fat, age
• female: decreased alcohol dehydrogenase in stomach and increased body fat
• medication
• concentration of alcohol in beverage
• usage (abstainers vs regular)

Question 9

general absorption rates

Answer 9

• plateau ~1 hr after consumption
• peak levels: 15 minutes later
• drink type affects absorption

Question 10

distribution

Answer 10

• alcohol dissolves in water therefore distributed entirely in body water
• crosses bbb & placental barrier
• circulates through lungs & vaporizes in air

Question 11

excretion

Answer 11

• some alcohol is excreted through breath sweat and urine
• most metabolized in liver (~90-98%) at a rate of 1 standard drink/hr

Question 12

2 step metabolisation process in the liver

Answer 12

1. alcohol is converted to acetaldehyde by alcohol dehydrogenase
2. acetaldehyde is converted into acetate; which escapes into bloodstream, some acetate then converted to acetyl-coenzyme A
   acetyl-coenzyme A converted to water and CO2

Question 13

excretion

Answer 13

• vary greatly between individuals (avg ~10-20mg/100ml/hr)
• metabolism depends on drinking experience
• eating speeds metabolism of alcohol
• excretion of methanol

Question 14

Microsomal ethanol-oxidizing system (MEOS)

Answer 14

• also responsible for metabolism of alcohol
• increased activity with continuous drinking - heavy drinkers metabolize quicker
• metabolizes barbituates - cross-tolerance

Question 15

interesting features of alcohol

Answer 15

1. alcohol affects a variety of tissues
2. need large dose to have an effect
3. no drugs act as complete antagonists to all of the effects of alcohol
   - alcohol does not work directly on specific receptor sites, but affects many sites of action

Question 16

glutamate (excitatory NT)

Answer 16

• alcohol decreases functioning at NMDA receptor (blocks ion channel)
• chronic exposure causes up-regulation of NMDA & glutamate
• NDMA receptors in hippocampus, glutamate & GABA neurons in prefrontal cortex

Question 17

GABAa-receptor-ionophore complex

Answer 17

-orthosteric & allosteric sites - alcohol increases GABA effects (decreases nueral activity) - so alcohol acts as a positive allosteric modulator

Question 18

GABAb (metabotropic) receptors

Answer 18

• in ventral tegmental area less inhibition of DA release into nacc
• agonists decrease alcohol consumption, reinforcement, motivation & craving
• chronic alcohol exposure leads to changes in this receptor too

Question 19

5-HT

Answer 19

alcohol stimulates serotonin receptor

Question 20

alcohol also affects

Answer 20

• second messengers
• monoamine oxidase
• glycine
• acetylcholine
• endogenous opiod systems

Question 21

effects on the body

Answer 21

• dialation of blood vessles - flushing (but decrease in body temp)
• increased urination

Question 22

effects on sleep

Answer 22

• induces sleep but does not increase total sleep time (exception: chronic uses: increases insomnia)
• decreases REM(1st part of sleep at low doses, whole night at higher doses, tolerance ~3 days)
• REM rebound effects up cessation

Question 23

effects of perception

Answer 23

• at high doses decreases absolute & difference thresholds for vision
• decreased visual acuity
• decrease peripheral vision
• decreased sensitivity to smell, taste and pain

Question 24

subjective effects

Answer 24

• biphasic effect re time and dose - but not for everyone (feeling of euphoria)
• stimulant like effects may cause greater risk of abuse

Question 25

effects on performance

Answer 25

- slowed reaction time - decreased hand-eye coordination - decreased speed and accuracy - decreased vigilance - decrease memory (storage and retrieval, en block blackout, grayout) - sensitivity of organs in the inner ear responsible for balance

Question 26

effects on behaviour

Answer 26

- disinhibition - talkative, excitable, cheerful - sleepy, unconsious - nausea, vomiting

Question 27

effects on driving

Answer 27

- impairs driving performance ~ 0.5-0.8 - reflected in crash statistics

Question 28

conditioning

Answer 28

- reinforcing properties of alcohol are dose dependent - decreased shock avoidance - increased response rates that have been paired with shock - similar effects in humans - alcohol decreases effect of aversive stimuli

Question 29

discriminative properties

Answer 29

- easy discrimination from saline - generalised to barbituates - can be block by serotonin receptor blockers & opioid receptor blocker but not dopamine D2 blocker

Question 30

self-administration in animals

Answer 30

- rats will drink in small doses, unless forced consumption - deprived of food & water/ or paired associations - generally, rats will self-administer sporadically, with periods of abstinence

Question 31

self-administration in humans

Answer 31

- usually high consumption - depends on culture, gender, age, availability

Question 32

acute tolerance

Answer 32

occurs while still drinking - esp to the subjective feeling of intoxication

Question 33

chronic tolerance

Answer 33

- develops v quickly within weeks for humans - does not develop equally for all effects

Question 34

metabolic tolerance

Answer 34

stimulation of alcohol dehydrogenase & MEOS

Question 35

conditioned tolerance

Answer 35

- hypothermic effects - environmental tolerance

Question 36

early minor syndrome

Answer 36

- can occur while still drinking but usually > 8-12 hours - agitation, tremors, muscles cramps, vomiting, nausea, sweating, dreams - usually over after 48 hours

Question 37

late major syndrome - delirium tremens

Answer 37

- 2 days of minor symptoms follow by disorientation, confusion, hallucinations, & seizures - last 7-10 days - can cause death if not managed

Question 38

alcohol poisoning

Answer 38

- .3-.4 = unconscious - .5 = death from respiratory failure <1-2 hours

Question 39

hangovers

Answer 39

esp dangerous when have epilepsy, heart disease or diabeters

Question 40

socio-cultural effects

Answer 40

- accidents - relationships - finances - criminal behaviour

Question 41

effects on reproduction - acute doses

Answer 41

- small doses we see disinhibition - large doses decreases sexual arousal

Question 42

effects on reproduction - chronic use

Answer 42

- loss of interest in sex - impotence; shrinking testes - menstrual dysfunction - spontaneous abortion - fetal alcohol syndrome (cognitive impairments, poor coordination, decreased birth weight, facial characteristics, malformed organs

Question 43

effects on liver function

Answer 43

- hepatitis - cirrhosis - decrease immune functioning

Question 44

effects on nervous system

Answer 44

- korsakoff's syndrome (memory loss disorder) - epilepsy - dementia - peripheral neuropathy (brain and spine damage, causing numbess)

Question 45

cancer

Answer 45

- mouth, throat and liver - increased risk with smoking

Question 46

heart disease

Answer 46

alcoholic cardiomyopathy - cirrhosis of the heart

Question 47

pharmacotherapies

Answer 47

- acamprosate (campral) - decrease glutamate activity - naltrexone - opioid receptor antagonist - disulfiram (antabuse) - blocks acetyldehyde dehydrogenase