Alcoholism Flashcards

1
Q

What are the primary neurotransmitters of the brain?

A

GABA -inhibitory

Glutamate - stimulatory

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2
Q

What are the secondary neurotransmitters?

A
Dopamine
Serotonin 
Noradrenaline 
ACh
Endogenous opiods 
These add tone, valence and emotion to the primary process
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3
Q

How do full agonist opiates work? (E.g. Heroin)

A

Act on the neurotransmitter pathway, but with a much greater effect than the natural transmitter

  • the drug hijacks the natural transmitter system
  • normal levels of stimulation are now not enough in comparison = addiction
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4
Q

How does alcohol cause addiction?

A

It indirectly stimulates the endogenous opiate system
- enhances the action of the inhibitory neurotransmitter GABA
This enters the synaptic cleft and binds to its receptors, opening chloride channels and hyperpolarising the membrane, lowering cell excitability

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5
Q

Some drugs work by acting on dopamine, how do they do this?

A

Stimulant drugs increase energy and stamina by increasing synaptic levels of dopamine
Some drugs increase dopamine availability in other brain regions; nucleus accumbens and prefrontal cortex
Normally the reward circuit in the brain is activated by food, water and sex
- drug abuse produces a greater effect on the reward system, and so the brain directs normal drives away from the natural reinforces and towards the drug

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6
Q

Define alcohol dependence?

A

An individual is physically or psychologically dependent on drinking alcohol - access to alcohol is the thing that takes on greatest value in their life

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7
Q

What criteria must someone fit to be diagnosed as alcohol dependent?

A

3 out of the 7 following things

  • tolerance
  • withdrawal symptoms
  • used in larger amounts or for longer periods than intended
  • persistent desire or unsuccessful efforts to cut down
  • time is spent obtaining alcohol
  • social, occupational and recreational pursuits are given up or reduced due to alcohol use
  • use is continued despite knowledge of alcohol related harm
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8
Q

What is the difference between dependence and abuse?

A

Dependence includes tolerance and withdrawal

Abuse can still include binge drinking

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9
Q

What is tolerance?

A

Reduced sensitivity requires that higher quantities of alcohol must be consumed in order to reach the same effects as before tolerance was established

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10
Q

What is reverse tolerance?

A

A liver damaged by chronic alcohol use, builds up fat and scar tissue
This reduces the ability of the liver to metabolise or break down alcohol and small amounts can lead to high blood alcohol concentrations

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11
Q

What does a persons alcohol tolerance depend on?

A

Activity of alcohol dehydrogenase - found in the liver and in the blood

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12
Q

What is a unit of alcohol?

A

10ml or 8g of pure alcohol

- equates the amount the average adult can process in one hour

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13
Q

What are the normal alcohol limits?

A

Advised not to drink more than 14 units a week, and should be spread out over a few days
- should include some days of abstinence

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14
Q

What substance is most alcohol metabolised to?

A

Acetaldehyde

  • a highly reactive and toxic substance
  • responsible for physical damage caused by excessive alcohol consumption
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15
Q

What is acetaldehyde metabolised to?

A

Acetate

- non toxic and concentrations in tissues is low

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16
Q

What is produced during oxidation of excess alcohol?

A
Lactic acid
Keto acid
Retention of uric acid
Hyperlipidaemia 
Accumulation of fat in the liver
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17
Q

What are the two pathways of alcohol metabolism?

A

Cytoplasmic alcohol dehydrogenase (CDH)

Microsomal ethanol oxidising system (MEOS)

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18
Q

Describe the cytoplasmic alcohol dehydrogenase system

A

It is the main, non-inducible route.
Alcohol is metabolised to acetaldehyde by alcohol dehydrogenase in the cytosol of cells
Acetaldehyde is then oxidised to acetate by acetaldehyde dehydrogenase in the mitochondria

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19
Q

Describe the Microsomal ethanol oxidising system

A

This is an inducible system, and takes excess alcohol the CAD system can’t handle
Alcohol is oxidised in acetaldehyde by the action of CYP2E1 in the SER
This reaction gives of a ROS as a byproduct
Then, acetaldehyde is oxidised to acetate in the mitochondria by the action of acetaldehyde dehydrogenase

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20
Q

Describe the acute physical injuries associated with drinking alcohol.

A
Accident and injuries 
Acute alcohol poisoning 
Aspiration pneumonia 
Oesphagitis
Malory-Weiss syndrome 
Gastritis 
Pancreatitis 
Cardiac abnormalities 
Cerebrovascular accidents 
Neuropraxia 
Myopathy
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21
Q

List the chronic problems that can arise from alcohol abuse.

A
Accidents and injuries 
Oesphagitis
Gastritis 
Malabsorption 
Pancreatitis 
Malnutrition 
Liver damage 
Systemic hypertension
Cardiomyopathy 
Coronary heart disease
Cerebrovascular accidents 
Brain damage 
Peripheral neuropathy 
Osteoporosis - alcohol directly onto bone reduces bone mass
Skin disorders
Malignancy 
Sexual dysfunction 
Foetal damage
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22
Q

Describe the relationship between alcohol and chronic pancreatitis.

A

Alcohol use can cause progressive and irreversible damage to the pancreas gland
Pancreatic calcification and gland distortion
Main clinical features are pain coupled with malabsorption/maldigestion and diabetes - main problem is continuous epigastric pain

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23
Q

Describe how alcohol can cause fatty liver.

A

Decreased mitochondrial fatty acid beta-oxidation (alcohol metabolism prioritised)
Increased endogenous fatty acid synthesis
Enhanced delivery of fatty acids to the liver
Deficient incorporation or export of triglycerides as VLDL

24
Q

Describe how alcohol can cause hepatitis.

A

Some present with jaundice, poor clotting and fluid retention
Acetaldehyde damages liver cell membranes
Free radical production also causes hepatocellular damage

25
Describe how alcohol can cause cirrhosis.
Damaged membranes prevents detoxification of chemicals, causing scarring and necrosis Acetaldehyde causes fibrosis by stimulating collagen deposition by hepatic Stellate cells Inflammation is caused by acetaldehyde and ROS, damages the cell membrane
26
Which brain damages are likely to occur during alcohol abuse?
Korsakoff-Wernicke's syndrome Dementia Cerebellar atrophy Central pontine myelinosis
27
What is Wernicke-Korsakoff syndrome?
Confusion, nystagmus and ataxia Caused by thiamine deficiency - lack of thiamine means the mitochondria are less protected against free radicals, and damage occurs
28
Describe cerebellar atrophy.
Characterised by various degrees of ataxia - affects trunk and lower limbs (upper limbs are little affected) Atrophy of the cerebellum - mainly in anterior and superior vermis
29
List the general characteristics of alcohol abuse.
Spider nevi - found only in distributions of the IVC/SVC Telangiectasia - broken veins Facial mooning - face appears round and eye-lids appear puffy Parotid hypertrophy Palmar erythema - beginning on hypothenar border of the hand Dupytren's contracture - thick palmar fascia Gynaecomastia
30
What are the social effects of alcohol?
Social problems Psychological problems Cognitive impairment
31
When is the most vulnerable period for alcohol abuse during pregnancy?
Weeks 4-10
32
What effects does alcohol exposure have during the 1st and 3rd trimester?
1st - Organ and craniofacial development | 3rd - significant effect on growth
33
What are the symptoms of foetal alcohol syndrome?
``` Small head Small ridge between nose and upper lip Small, wide-set eyes Thin upper lip Hyperactivity Below average height and weight Lack of focus Poor coordination Delayed development and problems in thinking, speech, movement and social skills Poor judgement Problems seeing/hearing Learning disabilities Intellectual disability Heart problems Kidney defects and abnormalities Deformed limbs and fingers Mood swings ```
34
What psychological therapies are available for alcohol addicts?
Brief intervention Barriers to change Aims
35
Describe a brief intervention
Focused on those who drink at hazardous levels Consists of - an assessment of recent alcohol intake - provision of information on harmful drinking - clear advice on options supported by relevant literature - contact details of local agencies Motivational interviewing - let patient arrive at their own decision Try to avoid arguments and confrontations
36
Describe common barriers to change.
Dependence - psychical (careful withdrawal from alcohol) - psychological (find trigger for drinking) - devise techniques for refusing drinks, develop and rehearse diversionary activities Stress - alcohol relaxes people in stressful situations (counselling and cognitive behavioural therapy) - environment Habit - difficult to break a habit (keep a diary during problem times) - hopelessness and pessimism (no point in trying because they won't be able to sustain it)
37
What are the aims at the end of the interview?
Set goals - specific, attainable and instantly rewarding Involve the family - reinforce decisions Identify underlying psychiatric or psychological problems Identify barriers to changes - eliminating these makes treatment easier Engender a positive attitude
38
Describe all thecognitive and behavioural therapies.
Cognitive and behavioural therapies - individual learns to identify triggers to drinking and finds new ways to cope with them Solution focused relapse prevention therapy Stress management and relaxation therapy Counselling - seeks to clarify psychosocial factors underlying alcoholism Family therapy
39
Describe the mechanism of Disulfiram.
Inhibitor of alcohol dehydrogenase If someone on this drug imbibes alcohol, blood acetaldehyde concentrations increase significantly, producing a flushing reaction May be accompanied by nausea, vomiting and tachycardia
40
Describe the mechanism of action of Naltrexone.
Opiate receptor antagonist - stops alcohol ingestion firing the pleasure pathway, and the experience has no joy for the person 50mg daily dose for 3-4 months
41
Describe the mechanism of action of Acamprosate.
Functional glutamate antagonist - again, modification the activity of the neurotransmitter in order to decrease the 'reward effects' from consumption of alcohol
42
What are the self-help groups available for alcohol addicts?
Alcoholics Anonymous AIAnon AITeen Online websites
43
What is the sneaky third option for alcohol metabolism?
Alcohol is oxidised to acetaldehyde via catalases in the peroxisomes ROS is also given off in this pathway
44
What are the consequences of acetaldehyde production?
Binds to proteins and DNA; immunogenic | Stimulates collagen production by Stellate cells
45
What are the consequences of acetate production?
Increased acetyl-CoA promotes inflammation by histone acetlyation
46
What are the consequences of an increasing NADH/NAD ratio?
Increased fatty acid synthesis Reduced fatty acid oxidation Promotion of steatosis
47
What are the consequences of non-oxidative metabolism?
Fatty acid ethyl ester production and increases steatosis
48
What are the consequences of ROS production?
Largely through MEOS, but catalase activity may also contribute Production of hydrogen peroxide and superoxide ions Activates redox-sensitive transcription factors, which leads to increase TNF-alpha production Promotes lipid peroxidation which promotes inflammation and damages mitochondrial membranes = apoptosis
49
What is another factor in how alcohol can cause liver damage?
Increased intestinal permeability leads to portal circulation endotoxaemia This promotes the action of Kupffer cells which in turn promot liver injury
50
What molecules does the hepatocyte produce when activated by alcohol?
``` TNF - activates ceramide - increases ROS concentrations IL-8 - activates neutrophils - increases ROS concentrations ```
51
Describe the intrinsic pathway of apoptosis.
Initiated by oxidative stress Leads to leakage of pro-apoptotic factors from the mitochondria (I.e.cytochrome-c) regulated by Bcl-2 proteins Pro-apoptosis factors from mitochondria activate cascades leading to cell degradation
52
Describe the extrinsic pathway of apoptosis.
Initiated by TNF-alpha Binding to TNF receptors leads to caspase activation via FADD (FAS-associated death domain) and TNF receptor-associated death domain proteins
53
What is the difference between apoptosis and necrosis?
Apoptosis is a natural cell death, stimulated by signals and is to the benefit of the organism as a whole While necrosis is traumatic cell death, stimulated by factors external to the cell and is fatal
54
What is glutathione?
A molecule that protects mitochondria | - requires zinc for its synthesis
55
How does alcohol affect glutathione?
Chronic liver disease affects the synthesis of glutathione, leaving the mitochondria more susceptible to damage by the ROSs