Alcohol Misuse Flashcards
How are units of alcohol calculated?
(volume)(% of alcohol)/10
What does higher risk drinking mean?
drinking 35units of alcohol weekly
What does increased risk drinking mean?
drinkign 15-35 units of alcohol weekly
What are the UK guidelines for low risk drinking?
no more than 14units of alcohol weekly (spread over 3 days/more)
What is alcohol dependence syndrome?
- Strong desire to consume alcohol
- difficulty in controlling consumption
- withdrawal state & tolerance
- neglect of interests/pleasures due to alcohol use
- Persistence of use despite harmful effects
Which range of tools are available to screen alcohol misuse?
- AUDIT (hazardous drinking)
- CAGE (alcohol abuse & dependence)
- TACE {T-tolerance}
- TWEAK (in pregnancy) {W-worried}
- MAST (full version in psych)
- PAT (for A&E)
- FAST (for A&E)
What investigations are available to screen for alcohol use
- GGT (liver damage)
- carbohydrate deficient transferrin-identifies drinking 5/more units a day for 2 weeks/more
- mean corpuscular volume (alcohol is most common cause of raised MCV)
What specialists interventions are available?
detoxification-pt becomes alcohol free
relapse prevention-psychosocial and pharmacological interventions aimed at maintaining abstinence following detoxification
How does alcohol affect the excitatory NMDA
receptors?
Alcohol inhibits the action of excitatory NMDA ion channels which leads to upregulation of receptors in chronic use
How does alcohol affect inhibitory GABA receptors?
it stimulates the inhibitory GABA-A ion channels which leads to downregulation of receptors in chronic use.
What is the overall effect of alcohol withdrawal (loss of inhibition of NMDA ion channels and loss of stimulation of GABA-A ion channels)?
Excess of glutamate activity (lead to seizures & delirium) and reduced GABA inhibition (lead to tremors, diaphoresis, tachycardia & seizures). Excess glutamate is toxic to nerve cells leading to CNS excitability and toxicity
When does alcohol withdrawal symptoms begin
first symptoms occurs within hours of abstinence and peaks at 24-48h
What are symptoms of alcohol withdrawal syndrome?
tremors, restlessness, anxiety, N+V, LOA, insomnia
What are the signs of alcohol withdrawal syndrome?
tachycardia, systolic hypertension
What other complications may occur from alcohol withdrawal syndrome?
- generalised seizures
- delirium tremens (usually 3 days into withdrawal and presents as confusion & sympathetic overdrive which can lead to cardiovascular collapse)
How long does alcohol withdrawal syndrome usually last?
5-7 days
What are the symptoms of delirium tremens?
- confusion/disorientation
- fever
- hypertension
- hallucinations (visual & auditory)
- paranoid ideation
What is the management for alcohol withdrawal syndrome?
- benzodiazepines
- acts on GABA-A receptors
- Use longer acting agents ie diazepam & chlordiazepoxide
- Titrate against severity of syndrome and reduce gradually over 7 days/more - vitamin supplementation
- parenteral thiamine (prevent wernicke’s encephalopathy)
- increase dose if wernicke’s suspected
What other supportive management can be carried out?
- adequate hydration
- anti-emetic
- analgesia
- treat intercurrent infections
What can be done for relapse prevention?
- Disulfiram (antabuse)
- Acamprosate
- Naltrexone (first line agent for relapse prevention)
What is the mechanism of action of disulfiram
- inhibits metabolism of alcohol
- inhibits acetaldehyde dehydrogenase which leads to accumulation of acetaldehyde when it interacts with alcohol
- this causes the symptoms of a “hangover” to occur almost immediately
What happens when disulfiram is taken with alcohol?
- flushed skin
- tachycardia
- n&v
- arrhythmias
- hypotension
What is the mechanism of action of acamprosate?
- acts centrally on glutamate and GABA systems
- reduces cravings with modest treatment effect
- start as soon as detoxification is complete
- continue through relapses
- *side effects
- headache
- diarrhea and nausea
What is the mechanism of action of naltrexone?
opioid antagonist and reduces reward from alcohol