Alcohol Flashcards
which pathways are switched on to metabolise alcohol in heavy drinkers
MEOS pathways and CP450
what are the consequences of the MEOS pathway
- citric acid cycle inhibition - switch to anaerboic metabolism - lactic acid build up
- inhibits hepatic gluconeogenesis - makes you hungry, can push diabetics into hypo
- impaired fatty acid oxidation - trigylceride accumulation in the liver
what effect does alcohol have on the heart
negative inotrope - tachycardia to compensate
how do you calculate alcohol units
(ABV x vol) / 1000
what is high risk drinking
>35 units a weel
what is low risk drinking
Men and women should not regularly drink more than 14 units of alcohol a week. Ideally, this should be spread evenly over three days or more
what is no risk drinking
there is no such thing!
what is TWEAK used for
screen for alcohol problems in pregnant women
which alcohol questionnaires are used in A and E
PAT and FAST
what is the purpose of CAGE screening tool
detect alcohol abuse and dependence
what lab tests can be done if chronic drinking is suspected
GGT, MCV, triglycerides
what is the science underlying the carbohydrate deficient transferrin test
- Transferrin transports iron in blood, normally has 3-5 carbohydrate side chains attached. Misuse of alcohol gives higher proportion of transferrin to less carbohydrate side chains, hence the term ‘deficient’
- Misuse of alcohol gives higher proportion of transferrin to less carbohydrate side chains, hence the term ‘deficient’
what is CDT used for
to detect heavy alcohol consumption, it is raised proportionally to alcohol intake and reflects the chronicity of drinking
how is CDT performed
blood tets
who uses teh CDT test
DVLA - to identify men drinking ≥5units/day for ≥2 weeks
is FRAMES used in dependent or non dependent people
non dependent - used to reduce alcohol consumption
outline FRAMES
- Feedback - review problems experienced because of alcohol.
- Responsibility – patient is responsible for change.
- Advice – advise reduction or abstinence.
- Menu – provide options for changing behaviour.
- Empathy – use empathic approach.
- Self-efficacy –encourage optimism about changing behaviour.
what does alcohol do to GABA and glutamate receptors
- Alcohol inhibits the action of excitatory NMDA-glutamate controlled ion channels (chronic use leads to upregulation of receptors)
- Alcohol potentiates the actions of inhibitory GABA type A controlled ion channels (chronic use leads to downregulation of receptors).
with this in mind, what happens when alcohol is withdrawn acutely
excess glutamate activity and decreased GABA activity - excitatory effect
CNS excitability and neurotoxicity
when do alcohol withdrawal symptoms peak
24-48 hours after
mild withdrawal symptoms
- Fine tremor, sweating, anxiety, hyperactivity, inc. HR, inc. BP, fever, anorexia, nausea, retching
moderate withdrawal symptoms
- Coarse tremor, sharking, agitation, confusion, disorientation, paranoia, seizures, hallucinations
severe withdrawal symptoms
- Risk of DT (medical emergency) around 48 hours, severe agitation, anxiety, confusion, delusions, hallucinations
- Circulatory collapse and death can occur
when does delirium tremens usually occur
3 days into withdrawal symtoms
what is delirium tremens
rapid onset of confusion
Confusion, disorientation, agitation, hypertension, fever, visual and auditory hallucinations, paranoid ideation.
is there a morbidity associated with delirium tremens
mortality 2-5% - CV collapse and infection
pharmacological management of alcohol withdrawal symptoms in the detoxifying period
benzodiazpines, usually diazepam or chlordiazepoxide as theya re long acting
why do benzodiazepines work
they are cross tolerant with alcohol as both potentiate GABA A receptors
how long are benzodiazepines given for
around 7 days, reduce dose gradually
name a withdrawal rating scale that can be usd as a guideline for prescribing
CIWA-Ar
complication sof benzodiazepines
over sedation and sometimes respiratory depression
why is vitamin supplementation considered
alcohol depletes thiamine stores inthe body, this may be a problem in chronic drinkers
given as prophylaxis against Wernickes Korsakoff syndrome
which vitamin is given
Thiamine (Pabrinex - B and C)
how is pabrinex adminstered
parenterally (IV or IM) as chronic alcohol consumption results in reduced absorption of thiamine
how does disulfiram work
- Inhibits aldehyde dehydrogenase, leading to accumulation of acetaldehyde if alcohol is ingested – flushed skin, tachycardia, nausea and vomiting, arrhythmias and hypotension (depending on volume congested)
- transient symptoms
what is the major problem with prescribing disulfiram and how can this be managed
patinet compliance - efficacy requires compliance
supervision of adminstration increases treatment success
what is Acamprosate used for
reduce ongoing symptoms associated with abstinence and cravings - relapse prevention
how does Acamprosate work
acts centrally on glutamate and GABA systems to normalise levels
AE of acamprosate
headache, diarrhoea and nausea
how does Naltrexone work
it reduces the rewarding and reinforcing effects of alcohol
- blocks stimulation of opioid receptors by endogenous opioids
- decreases dopamine release in VTA of midbrain (first step in reward pathway)
are brief interventions worth doing?
yes, very effective
average reduction in alcohol consumption of 45% at 12 months
who is the minimum unit price of 50p likely to benefit most
harmful drinkers and those living in poverty
