Alcohol Flashcards
Define alcoholic:
primary chronic disease characterized by impaired control over drinking, preoccupation with the drug alcohol, use of alcohol despite adverse consequences, and distortions in thinking
Define: dependence
needs 3 of 7 conditions over 12 months
- tolerance
- withdrawal symptoms
- ingestion in larger amounts
- persistent desire
- expenditure of increase time in drinking/recovering
- abandoning social/work activities
- continued ingestion despite problem
What does the DSM-5 state about alcohol abuse?
integrates alcohol abuse and alcohol dependence into alcohol use disorder (AUD)
- mild, moderate or severe subclassifications
- > 6 = severe
Is alcohol ever good for you?
Definitive data lacks proof of the cardiovascular benefits of alcohol whereas the harms are well established
What is 1 unit of alcohol?
10ml ethanol = 8 g ethanol
How is alcohol absorbed?
duodenum-jejunum over 80%
process of simple diffusion
rate is concentration dependent and related to stomach emptying
How is alcohol distributed following absorption?
rapidly distributed - rich blood supply = faster effect
crosses BBB easily
Volume of distribution equal to total body water - 0.6L/kg
differences between men and women - higher effect on women
fatter people high relative blood concentration - reason affects women more
How is alcohol metabolised?
98% by ADH to acetylaldehyde and then by ALDH to acetate
- acetylaldehyde is toxic and causes nausea, flushing and headaches
- there are genetic variations in ALDH
- ADH is rate limiting step
What is the normal clearance rate of alcohol?
6g/hour
How is alcohol excreted?
small amounts not metabolised and excreted unchanged
- in urine and breath - useful for detection
What is the pharmacological effect of alcohol?
Central nervous system depressant - (apparent stimulatory effects are due to depression of inhibitory control mechanisms in the brain)
GABA-A potentiation
NMDA antagonist - causing glutamate inhibition
effects on serotonin, opioid and dopaminergic neurotransmission (reward centres)
What is the legal driving limit in England and wales?
80mg alcohol /100ml blood
35 micrograms alcohol / 100ml breath
107mg alcohol / 100ml urine
What effect does alcohol have on CNS drugs ?
increased drowsiness/sedation
e.g. SSRIs, benzodiazepine, antihistamines
What effect does alcohol have on antihypertensives/cardiovascular drugs?
enhanced hypotensive effects
What effect does alcohol have on warfarin?
major changes in consumption of alcohol may affect anticoag control with coumarins
What effect does alcohol have on metronidazole / ketoconazole?
inhibits ALDH - gives you an awful hangover effect - like a disulfiram like reaction
What does disulfiram do?
certain drugs inhibit ALDH causing accumulation of acetylaldehyde
- used as an aversion therapy - help alcoholics stop drinking
What are the medical uses of alcohol?
local use - bacteriocidal swabs/gels
used in pharmaceutical solutions - awareness of their use in children
methanol/ethylene glycol poisoning - competitively inhibiting ADH - now fomepizole is more commonly used
What are the main medical / psychiatric problems associated with alcohol?
acute alcohol intoxication
alcohol withdrawal reactions - inc delirium tremens
chronic alcoholism
contributes to obesity epidemic
What are the characteristic features of acute alcohol intoxication and common causes of death?
AAI associated with violence, accidents, injuries, sexual victimisation and suicides
Common causes of death - aspiration from vomiting when reduces GCS or trauma
Beware of associated hypoglycaemia (esp. in children)
What is binge drinking classified as?
> 8 in males and >6 in females at once
What does the CAGE questionnaire stand for?
Cut down amount of drinking Annoyed by criticism Guilty feelings about drinking Eye opener in the morning - this questionnaire is not as sensitive in white females or pregnancy
What are a couple of other screening tests?
Fast and audit
When trying to diagnose an alcohol problem what physical examinations are carried out?
usually no findings Signs of chronic liver disease parotid enlargement rhinophyma peripheral neuropathy signs of withdrawal
When trying to diagnose an alcohol problem what laboratory tests are carried out?
FBC - macrocytosis in the absence of anaemia can be due to alcohol
U&Es - low urea
LFTs - raised transaminases
Gamma GT - elevated - if associated with liver pathology
INR - prolonged
What are the alcohol withdrawal symptoms at 6-12 hours?
insomnia tremulousness anxiety GI upset headache diaphoresis palpatations anorexia
What are the alcohol withdrawal symptoms at 12-24 hours?
alcoholic hallucinosis: visual, auditory or tactile hallucinations
What are the alcohol withdrawal symptoms at 24-48 hours?
generalised tonic clonic seizures
What are the alcohol withdrawal symptoms at 48-72 hours?
delirium tremens halluncinations disorientation tachycardia increase BP mild fever agitation diaphoresis
What are the principles of managing alcohol withdrawal?
ABC - resus
Prevention/ treatment of encephalopathy
Prevention/treatment of withdrawal
Prevention/treatment of complications
What is involved in the prevention/ treatment of encephalopathy?
vitamins-thiamine and other B vitamins
Severe deficiency states (e.g. wernickes) best treated by parenteral therapy
High potency vitamin B complex (parabrinex)- contains high dose thiamine (B1), riboflavin (B2), pyridoxine (B6), nicotinamide and vit C
2-3 pairs of ampoules every 8 hours
SE: potentially serious allergic reaction
Followed by..
- oral thiamine 200-300 mg daily
- and vit B compound strong 2 tabs TDS
What is involved in the prevention/ treatment of alcohol withdrawal?
Community / hosp setting
- benzodiazepines
treatment of symptoms / prevention of seizures
reactive- prescribe according to symptoms (clinical institute withdrawal assessment for alcohol (CIWA))
expectant - prescribe fixed dose
What is involved in the prevention/ treatment of complications and abstinence?
associated psychiatric problems
social interventions - AA, aquarius
pharmacological maintence of abstinence
- acamprosate - stabilises glutamate and GABA systems = reduces cravings, anxiety and insomnia
- naltrexone - opioid antagonist - helpful as an adjunct to alcohol dependence after withdrawal treated, reduce rate of relapse
- nalmefene - opioid receptor modulator - reduction of alcohol consumption - take 1-2 hours before drinking
- disulfiram - inhibits ALDH leading to flushing, sweating and nausea
