ALCOHOL DEPENDENCE Flashcards
what is alcohol
a by-product of the fermentation of various fruits and grains - drinking alcohol is a common widely accepted activity in most countries and cultures
fat and water soluble, readily diffuses across all cell membranes, peak blood levels are within 30-60min
blood alcohol concentration (BAC)
grams of alcohol in 100ml of blood
> 0.15% = significant impairment of balance, slurred speech, nausea, vomiting
> 0.30% = loss of consciousness, anaesthesia
easiest way to measure alcohol
measure alcohol through expired through respiration - breathalyzer (estimates BAC by analysing a sample of the breath which contains alcohol passed from bloodstream into the lungs)
alcohol’s moa
agonist effect on GABA receptor - increasing binding or influx of Cl- (CNS depressant)
GABA synapses control activity of different neuronal systems - glutamate, dopamine, opioids
many ‘neuropsychiatric effects’
chronic consequences of alcohol
- peripheral neuropathy and dementia caused by alcohol toxicity and vit B6 (thiamine) deficiency
- sleep disturbance, depression or anxiety
- overall malnourishment
alcohol effect on thiamine
- alcohol prevents conversion of thiamine to TPP in small intestine and interferes with its storage in the liver
how genetic variation impacts alcohol
(far east population) have an inactive form of aldehyde dehydrogenase - acetaldehyde is not further converted into acetic acid - so small amounts of alcohol result in toxic levels of acetaldehyde which cause nausea, vomiting, sweating and severe headache
how gender impacts alcohol metabolism
females have less alcohol dehydrogenase and metabolise 50% less than men
women have greater fat-to-muscle ratio - so less blood for proportional body weight, so have greater blood concentration in women then men
risks from alcohol
accidental injury
sexual misdemeanours
violence
CV disease
liver diseases
cancers
when is drinking alcohol considered a ‘problem’
once dependent on alcohol for day-to-day functioning - AUDIT (alcohol use disorder identification test) or CAGE questions
IBA (alcohol identification and brief advice)
a process of identifying people who maybe have alcohol issues via a structured conversation about alcohol consumption
brief intervention (not appropriate for dependency) - FRAMES
Feedback > patients personal risk or impairment
Responsibility > emphasise personal responsibility for change
Advice > suggest how to cut down/abstain
Menu > offer alternative options
Empathetic > listen reflectively, explore reasons for change
Self efficacy > enhance the pts belief in their ability to change
SADQ (severity of alcohol dependence questionnaire) is a 20 item questionnaire - scoring system
answers rated on a 4-point scale: never (0), sometimes (1), often (2), nearly always (4)
> 31 indicates severe alcohol dependence
16-30 indicates moderate dependence
<16 only a mild physical dependence
tests required for alcohol dependence
complete blood count (reduced vitamin B12 and folate levels can be red flags)
LFTs (AST/ALT >1.5)
management of alcohol withdrawal
- abrupt cessation can lead to withdrawal symptoms - BZs given to manage either by ‘symptom triggered approach’ or ‘fixed-dose regimen’
- delirium tremens is a serious withdrawal effect with high mortality - a type of agitated delirium approx. 72 hours after last drink
- need adequate fluid and nutritional replacement (parenteral thiamine or vit B with ascorbic acid Pabrinex IM)
CDP in treating alcohol withdrawal
chlordiazepoxide used long-acting, prescribed on a reducing dosage regimen over 5-7 days
starting dose based on symptom severity
treatment of alcohol withdrawal
- use BZs due to similarity in moa with alcohol (GABA mediated)
- BZs diminish the severity of the symptoms as neuronal systems begin to revert back to pre-alcohol states
- diazepam most common
drugs that reduce cravings to support abstinence
acamprosate
disulfiram
naltrexone
nalmefene
BUT also high placebo effect if engaging with any health professional and joining support groups (AA)
disulfiram moa
- irreversibly inhibits aldehyde dehydrogenase causing accumulation of acetaldehyde - sweating, nausea, facial flushing, tachycardia, hypotension
disulfiram monitoring and dose
- intensity to reaction is dose-dependent (loading dose of 400-800mg) followed by 100-200mg maintenance
- start 24 hours after last drink
- monitor every 2 weeks for 1st 2 months, then monthly
- liquid or tablets - supervised 2 or 3 times weekly as enzyme inhibition is irreversible and clinical effect lasts 7-10 days
acamprosate moa
- GABA A agonist and glutamate (NMDA) antagonist - reduces craving
- 7 days to reach therapeutic levels so can start immediately after detox
- side effects: diarrhoea, abdominal pain, nausea, pruritis
acamprosate dose and monitoring
- daily dose is 1998mg (666mg tds) for >60kgs
- usually over 6 months treatment
- determine renal and hepatic function prior to use
nalmefene moa
opioid antagonist (mu and delta receptors AND a partial agonist at kappa receptors)
side effects: nausea, vomiting, sweating
nalmefene dose
as required use i.e. 18mg tablet taken 1-2 hours before exposure to alcohol
naltrexone moa
non-selective opioid antagonist
side effects: nausea, headache, abdominal pain
naltrexone dose
start at 50mg daily - usually for 6 months duration
hepatoxicity at high dose
avoid opioid analgesia
drug of choice when co-morbid with schizophrenia
naltrexone or acamprosate preferred
signs and symptoms of FAS
- low body weight
- poor coordination
- hyperactive behaviour
- difficulty with attention
- poor memory
- difficulty in school (esp. maths)
- learning disabilities
- speech and language delays
