Substance use disorder: alcohol Flashcards
How do you calculate units of alcohol? What is the recommended weekly limit for men and women?
Units = Volume (L) * ABV (%)
e.g. a 750ml bottle of wine, strength 12% has 750/1000 *12 = 9 units
Both men and women should drink no more than 14 units a week. If you do, it is best to spread this evenly over 3 days or more.
or [Volume (mls) x Alcohol by Volume ABV (%)] / 1000
What are the effects of alcohol on the CNS?
Complex interplay between excitatory and inhibitory systems:
- Dopamine - increased in nucleus accumbens (mesolimbic system reward pathway)
- NA - inceased, enlivening effect
- Opioids - endougenous increase causing analgesia, pleasure and stress reduction
- GABA-A - anxiolytic and ataxic effects, amnesia and sedation
- Glutamate - blocking its NMDA-R, so opposing its effects and cauing amnesia and depressant effect
- Serotonin - nausea and pleasure; different levels may cause varying presentations of anxiety and aggressiveness
What are the symptoms of acute alcohol intoxication?
- slurred speech
- impaired coordination
- impaired judgement
- can lead to hypoglycaemia and coma
What are the symptoms of alcoholic ketoacidosis?
- nausea
- vomiting
- abdominal pain
- alert and lucid (unlike DKA)
Aetiology: when alcoholics miss meals or vomit then episodes of starvation lead to fat rather than carbohydrate metabolism, which generates ketone bodies.
Diagnosis: metabolic acidosis with raised anion gap due to high ketones BUT glucose nomal.
Management: IV saline + dextrose + thiamine
What is the ICD-10 criteria for dependance syndrome?
- Compulsion - strong desire to take the substance
- Control - difficulties in controlling substance-taking behaviour (onset, termination, levels)
- Withdrawal - physiological withdrawal when substance use has ceased or have been reduced
- Tolerance - increased doses required to achieve originally porduced effects by lower doses
- Salience - little alternative pleasure or interests due to psychoactive substance use, increased time needed to obtain or take the substance or to recover from its effects
- Persistance - with substance use despite clear evidence of overtly harmful consequences, such as harm to liver through excessive drinking, depressive mood states consequent to periods of heavy substance use or drug-related impairment of cognitive functioning
3 or more of the following manifestations should have occurred together for at >1 month or, if persisting for periods of <1 month, should have occurred together repeatedly within a 12-month period.
In addition to these dependence features, what else may be seen in alcohol dependence?
Narrowing of the drinking repertoire
Which drugs target GABA-A?
- Alcohol
- Z-drugs
- Benzodiazepines
- Gamma hydroxybutyrate (GHB)
- Baclofen (GABA-B)
Which are long vs short-acting benzodiazepines?
Diazepam, clonazepam, chlordiazepoxide - long acting
Midazolam, lorazepam - short acting
What is the MOA of benzodiazepines?
- Positive allosteric modulators of GABA-A
- When it binds, the receptor has greater affinity for GABA
- Increased flow of Cl- channels occyrs hence hyperpolarisation of the post-syanaptic membrane
- Hence neurone has reduced excitability
Do benzodiazepines cause tolerance or dependence?
Both
What is the stages of change model?
What questions can you ask in the history to screen for alcohol dependence?
CAGE questionnaire
- Have you tried to Cut down drinking?
- Have people Annoyed you by suggesting you do so?
- Have you felt Guilty about drinking?
- Have you needed an Eye-opener (early morning drink)?
_>_2= positive for alcohol disorders
OR FAST questionnaire (below)
Which tools can you use to assess severity and nature of alcohol misuse?
Identification:
- AUDIT (below) – alcohol use disorders identification test (>15 requires comprehensive assessment)
Severity:
- SADQ – severity of dependence
Withdrawal:
- CIWA-Ar – clinical institute withdrawal assessment of alcohol scale (for severity of withdrawal)
Social:
- APQ – alcohol problems questionnaire (assess the nature and extent of the problems arising from alcohol misuse)
What additional investigations might you do in alcohol dependence?
- Bloods: FBC, LFT, B12, folate, U&E, clotting screen, glucose
- Blood alcohol level or breathalyser
- Urine drug screen
How should you approach a consultation regarding alcohol misuse?
- Establish goals - e.g. usually abstinence
- Motivational interviewing - explore problems and encourage belief in ability to change
- Biopsychosocial approach
Summarise the management of alcohol dependence.
Biological:
- Medication e.g. benzodiazepines, acamprosate, disulfuram.
- Thiamine if likely deficient in diet
Psychological:
- Treat underlying mental health problems
- CBT - 12 sessions, weekly
- Behavioural couples therapy
Social:
- Addess needs of family/carer’s e.g. self-guided help or family therapy sessions, carer’s assessment
- People who are dependent on alcohol should be advised that they are required by law to notify the DVLA
- If homeless offer residential rehabilitation for maximum 3 months
- Provide information about AA, SMART Recovery, and Change, Grow, Live (CGL)
What are the symptoms of alcohol withdrawal and when do they occur?
Early: symptoms start at 6-12 hours
- tremor,
- sweating,
- tachycardia,
- anxiety
Peak incidence of seizures at 24-36 hours: seizures with visual hallucinations
Peak incidence of delirium tremens is at 48-72 hours:
- coarse tremor,
- confusion,
- delusions,
- auditory and visual hallucinations,
- fever,
- tachycardia
What are the symptoms of delirium tremens? When do they occur?
Usually 24-72 hours after alcohol consumption has been reduced or stopped
Signs of altered mental status (compared to no change in normal withdrawal symptoms) e.g.
- Hallucinations (auditory, visual, tactile)
- Confusion
- Delusions
- Severe agitation
Signs of chronic alcohol abuse
What is the management of delirium tremens? What should you never give before pabrinex?
- Alcohol detox: CIWA is widely used to help decide the regimen.
- Benzodiazepines: long acting such as Chlordiazepoxide (Librium) unless there is significant hepatic impairment; prescribed as a ‘reducing regimen’ often over 7-10 days in hospital.
- Pabrinex: one pair ampoules once daily for 5 days (prophylaxis Wernicke)
Don’t ever give IV dextrose to a heavy drinker before giving prabrinex (glucose loading can precipitate Wernicke’s in thiamine deficient patients)
What medications and regimens are used to manage acute alcohol withdrawal?
Fixed-dose or symptom-triggered regimen
1st line - chlordiazepoxide or diazepam (if liver impairment: lorazepam)
- Titrate initial dose based on severity of alcohol dependence/ daily alcohol consumption
- Gradually reduce the dose over 7-10 days
- Give no more than 2 days medication at a time (installment dispensing)
Why is lorazepam offered for withdrawal with hepatic impairment?
It has limited hepatic metabolism
What medications are used once alcohol withdrawal has been successful?
1st line: acamprosate + individualised psychological intervention
2nd line: disulfiram if above options are unsuccessful/unacceptable
- Usually prescribed for up to 6 months
- Baseline medical investigations before starting medication (including U&Es and LFTs)
NB: naltrexone not licensed for use in UK. Nalmafene may be used.
What is the MOA and effect of these medications?
- Acamprosate
- Disulfiram
- Naltrexone/nalmafene
Acamprosate - weak antagonist of NMDA receptors –> anti-craving
Disulfuram - inhibits acetaldehyde dehydrogenase –> hangover symptoms as soon as you drink a.k.a. Antabuse NB: warn patients that even small amounts (e.g. perfume, food, mouthwash) can cause the reaction
Naltrexone - mixed opioid antagonist esp. mu receptor
Nalmafene - opioid antagonist –> reduces consumption if started when drinking
Name 2 contraindications to disulfiram use.
- ischaemic heart disease
- psychosis
What factors would make you consider assisted withdrawal?
If one or more of the following are present:
- 30+ units/day
- 30+ on SADQ
- History of epilepsy, delirium tremens or withdrawal-related seizures
- Need concurrent withdrawal of alcohol and benzodiazepines
- Significant psychiatric comorbidity or significant learning disability
- Lower threshold for inpatient treatment in vulnerable groups (e.g. homeless, older people)
- Children (10-17) - should also receive family therapy for about 3 months
What is the regimen for community assisted alcohol withdrawal?
Pabrinex +
If >15 units/day or >20 on AUDIT -> community based assisted withdrawal
- e.g through organisations like CGL (Change, Grow, Live)
- Usually 2-4 meetings in the first week
- If complex, may need up to 4-7 days per week over a 3-week period
Management in specialist alcohol services if there are safety concerns
What is the difference in symptoms between Wenicke’s and Korsakoff’s?
COAT:
- Confusion
- Ophthalmoplegia
- Ataxia
- Thiamine deficiency
RACK:
- Retrograde amnesia
- Anterograde amnesia
- Confabulation
- Korsakoff syndrome
What is the pathophysiology of Wernicke’s encephalopathy? What is the management?
Lack of Vitamin B1 causes a peripheral neuropathy and leads to cerebellar degeneration giving ataxic signs
Management: IV infusion of thiamine (Vitamin B1)
What is the pathophysiology of Korsakoff’s syndrome?
This is the consequence of untreated Wernicke’s encephalopathy which leads to irreversible brain changes.
Define confabulation.
Confabulation –> symptom of memory dysfunction where patients make up stories to fill in gaps in memory
What questions is it important to ask in an alcohol history?
HPC:
- Type of alcohol
- Volumes and ABV (%)
- How often?
- Where?
- Alone?
- When do you start drinking?
- Binges or steady?
- Withdrawal symptoms?
- Triggering factors
- When did it start?
- Longest period of abstinence?
PMH:
- Detoxes in the past?
- Problems - social, work, physical, psychological
DH:
- Other substance use
- Drug use
- Mental health history
- Personal history
Forensic history
FH:
- FH of substance misuse
What are the adverse effects of alcohol on physical and psychological health?
