Substance use disorder, including relapse prevention and acute withdrawal from - alcohol

Description

Chronic relapsing disorder - loss of control over intake, continued use despite harm, tolerance and withdrawal
DSM-5-TR: 2+ of 11 criteria in 12 months (mild 2-3, moderate 4-5, severe 6+)
Withdrawal spectrum: uncomplicated withdrawal -> seizures -> delirium tremens
Wernicke-Korsakoff syndrome - thiamine deficiency complication, not withdrawal itself

~1 in 20 Australian adults meet criteria for alcohol use disorder in their lifetime
M>F, though the gap is narrowing
NHMRC 2020 guideline: <=10 standard drinks/week and <=4 on any one day to reduce lifetime risk
Withdrawal seizures in ~5-15% of untreated withdrawal; delirium tremens in ~5% (mortality 1-5% if untreated)

Chronic alcohol -> potentiation of GABA-A + inhibition of NMDA glutamate receptors -> CNS depression
Abrupt cessation -> unmasked GABA under-activity + NMDA/glutamate hyperactivity -> CNS hyperexcitability
- -> tremor, autonomic hyperactivity, seizures, delirium tremens
Wernicke's encephalopathy: thiamine (B1) deficiency from poor intake + malabsorption + depleted hepatic stores
- Glucose administration without thiamine can precipitate/worsen Wernicke's

Clinical (DSM-5-TR criteria) + collateral history
Screening: AUDIT (>=8 hazardous), AUDIT-C, CAGE
Withdrawal severity: CIWA-Ar score - guides symptom-triggered treatment
Ix: LFT (GGT, AST:ALT >2), FBE (macrocytosis), coagulation, thiamine level not routinely needed (treat empirically)
Delirium tremens: confusion + hallucinations (classically tactile/visual) + autonomic instability, typically 48-96h post last drink

1. Withdrawal - assess risk first

Risk factors for severe withdrawal: prior DTs/seizures, high intake, older age, comorbidity, concurrent benzodiazepine use
Symptom-triggered dosing (CIWA-Ar-guided) preferred; front-load high-risk patients with scheduled dosing
Benzodiazepines - diazepam or lorazepam (lorazepam preferred in hepatic impairment/elderly - no active metabolites)
IV/IM thiamine before or with any glucose - prevents/treats Wernicke's

2. Delirium tremens

High-dose benzodiazepines, often requiring escalating/very high doses; ICU if refractory
Antipsychotics only as adjunct for agitation, never as monotherapy (lower seizure threshold)

3. Relapse prevention (after withdrawal)

Naltrexone - reduces craving/reward, 50mg/day (contraindicated with concurrent opioid use/need)
Acamprosate - reduces glutamatergic hyperactivity, useful with hepatic impairment (renally cleared)
Disulfiram - aldehyde dehydrogenase inhibition -> aversive reaction; requires motivated, supervised patient
Psychosocial: CBT, motivational interviewing, mutual support (AA/SMART Recovery)

Withdrawal symptoms peak 24-72h, DTs classically 48-96h post last drink
Relapse common - most benefit from structured relapse-prevention pharmacotherapy plus psychosocial support
Long-term abstinence associated with reversal of some hepatic and cognitive changes; Korsakoff amnesia often irreversible

6 more sections, plus exam facts

Premium unlocks every note across every specialty, and the full exam fact library behind it.