Lecture 17 - alcohol dependance Flashcards
describe the components of alcohol and its dependance in the body.
Fat and water soluble, readily diffuses across all cell membranes, peak blood levels are within 30-60 mins
Blood Alcohol Concentration (BAC)= grams of alcohol in 100ml of blood. (80mg of alcohol in 100ml of blood is equiv to 0.08grams per 100ml) (0.08%)
what are figurative effects of BAC levels ?
more than 0.15 %= significant impairment of balance, slurred speech, nausea vomiting,
more than 0.30% = loss of consciousness, anaesthesia,
what is used to measure alcohol in a person?
Easier to measure alcohol expired through respiration- breathalyzer (estimates BAC by analysing a sample of the breath which contains alcohol passed from blood stream into the lungs)
Describe the mechanism of action of alcohol
Agonist effect on GABA receptor- increased binding or influx of Cl- (a CNS depressant)
GABA synapses control activity of different neuronal systems- glutamate, dopamine, opioids
Many ‘neuropsychiatric effects’
what does the sustained or chronic sue of alcohol lead to?
peripheral neuropathy and dementia caused by alcohol toxicity and vitamin B6 (thiamine) deficiency in specific midbrain.
alcohol prevents conversion of thiamine to TPP in the small intestine and interferes wits its liver storage.
it can cause sleep disturbance, depression or anxiety and overall malnourishment
how do the effects of alcohol occur in reference to aldehyde dehydrogenase?
genetic variation 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 causes nausea, vomiting, sweating and sever headaches
describe the metabolism of alcohol.
The metabolism of alcohol into acetylaldehyde and further into acetic acid depends on the availability of the coenzymes alcohol dehydrogenase and aldehyde dehydrogenase and coenzyme NAD.
how does alcohol affect men and women differently?
females have less and metabolise 50% less than men.
Women have greater fat to muscle ratio- so less blood for proportional body weight (As fat has lower blood supply than muscle)- so have greater blood conc in women than men for equivalent doses of alcohol
what are ways to manage the risk and from alcohol ?
- Avoid talking about ‘safe levels’ of consumption instead reduce the risk of further harm – this depends on age, genes, concurrent medication, general / co morbidities
- Risks include accidental injury, sexual misdemeanours, violence, CV disease, liver diseases, cancers.
- Becomes a problem once dependent on alcohol for day to day functioning – AUDIT (alcohol use disorders identification test) or CAGE questions- considered Cutting down your alcohol consumption, got annoyed by people criticising your drinking, felt guilty about your drinking, had a drink 1st thing in the morning (eye opener)
- Binge Drinking – twice the upper limit of the max daily drinking level (6 units for women, 8 units for men
what is the pharmacist intervention associated with alcohol consumption in a patient?
- Establish drinking patterns- Ask about alcohol consumption at any relevant opportunity.
- People with alcohol related probs may find it difficult to accept they have a problem and developed coping strategies to manage their drinking- Approach in a non judgemental and open manner.
- IBA (Alcohol Identification and Brief Advice)-a process of identifying people who may be have alcohol issues via a structured conversation about alcohol consumption.
- Consider concomitant health problems, cognitive functioning, readiness to change.
- Ensure questioning is sensitive to culture and faith.
what brief intervention should be addressed?
- Patient centred conversations- non judgemental
- Signpost to services/resources (alcohol awareness)
- Avoid sudden stop if severely dependent
Use FRAMES – 3-5mins - Feedback- patients personal risk or impairment
- Responsibility- emphasise personal responsibility for change
- Advice- suggest how the patient can cut down or abstain
- Menu- offer the patient alternative options for changing their drinking pattern
- Empathetic - listen reflectively, explore with the patient reasons for change.
- Self efficacy- enhance the patients belief in their ability to change
what is sued to assess the degree of dependant or harm of alcohol?
Subjective for the individual BUT various questionnaires used to assess the degree of dependence or harm.
e.g SADQ (severity of alcohol dependence questionnaire) is a 20 item questionnaire- centred on the drive to consume alcohol
Answers rated on a four-point scale: Almost never – 0, Sometimes 1, Often 2, Nearly always 3
> 31 or higher indicates “severe alcohol dependence”.
16 -30 indicates “moderate dependence”
< 16 usually indicates only a mild physical dependency.
Routine laboratory screening, including LFTs (aspartate aminotransferase (AST), alanine aminotransferase (ALT) the AST/ALT ratio is >1.5 OR gamma glutamyltransferase ↑GGT, complete blood count (high Mean Corpuscular Volume [MCV]) and reduced vitamin B12 and folate levels can be “red flags” .
what is the alcohol withdrawal timeline?
1: anxiety, insomnia, nausea and abdominal pain
2: high blood pressure, increased body temperature…
3: hallucination, fever, seizures and agitation
Abrupt cessation can lead to withdrawal symptoms- Benzodiazepines given to manage these either by a ‘symptom triggered approach’
or a ‘fixed dose regimen’
Delirium Tremens is a serious withdrawal effect with high mortality- a type of agitated delirium approx. 72hrs after last drink.
Need adequate fluid and nutritional replacement (parenteral thiamine or Vit B with ascorbic acid Pabrinex® im high potency
what drugs are used in maintaining abstinence of alcohol withdrawal?
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 has limited efficacy but thrice weekly supervised consumption may be superior to unsupervised daily acamprosate
what is the treatment of alcohol withdrawal?
For alcohol withdrawal i.e management of autonomic over arousal, fits or delirium tremens (DTs)
Use BZs due to similarity in mechanism of action with alcohol (GABA mediated) BZs diminish the severity of the symptoms as neuronal systems begin to revert back to pre-alcohol states
Chlordiazepoxide (CDP) used- long acting, prescribed on a reducing dosage regime over 5-7 days.
Starting dose based on symptom severity i.e 60-100mg/day.
Diazepam most often used- reduce by 1/6 of total dose per week – Usually by specialist services (might have patient in general medicine ward/community detox).
