Alcohol withdrawal

Withdrawal of alcohol in dependent users (detoxification) can lead to a rapid fall in blood alcohol concentrations, causing unpleasant symptoms that generally peak 12-48 hours afterwards (and are relieved by alcohol intake).

Mechanism

Alcohol inhibits the action of NMDA-glutamate controlled ion channels, leading to an upregulation of receptors with chronic alcoholism.  It also potentiates the action of GABA-A controlled ion channels, leading to a corresponding down-regulation of receptors.  In the acute withdrawal of alcohol, there is therefore an acute flood of excitatory (but neurotoxic) glutamate.  It is this that causes the symptoms.

Withdrawal syndrome

First symptoms can occur within an hour and usually peak at around a day.

  • Restlessness; tremor; sweating; anxiety; nausea; vomiting; loss of appetite; insomnia; tachycardia; systolic hypertension; generalised seizures

Delirium tremens (5%)

Often presents insidiously with night time confusion, disorientation, agitation.  Will do onto develop hypertension, fever, visual/auditory hallucinations and paranoid ideation.  It has a mortality of 2-5% (either cardiac collapse or infection), but usually resolves within 5-7 days.

Management

ABCDE!!

  • Benzodiazepines are used to blunt the withdrawal symptoms (they are cross-tolerant with alcohol- act on GABA-A receptors).  They should be titrated against severity and only long-acting forms are really used (diazepam for inpatients; chlordiazepoxide for outpatients).  BDZs should be withdrawn SLOWLY (>1wk) to avoid similar syndrome.
  • IM Thiamine (vit B1) to prevent the onset of Wernicke’s encephalopathy and subsequent Korsakoff’s syndrome.  This should be given for at least 5 days and, ideally, oral thiamine continued for at least a year.
  • Adequate hydration (IV fluids); analgesia; antiemetics; and treatment of comorbid conditions are also important.

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