Thiamine Dosing in AUD with Major Neurocognitive Disorder
Continue 200mg daily thiamine indefinitely in this patient with alcohol use disorder history and major neurocognitive disorder—do not reduce to 100mg. 1
Rationale for Maintaining Higher Dose
Your patient requires ongoing therapeutic dosing rather than standard maintenance supplementation due to multiple high-risk factors:
Alcohol use disorder creates permanent absorption deficits: Chronic alcohol consumption causes irreversible gastrointestinal damage that impairs thiamine absorption even after abstinence, requiring higher oral doses to achieve adequate tissue levels 1, 2
Major neurocognitive disorder indicates established neurological damage: The presence of major NCD suggests prior thiamine deficiency has already caused permanent brain injury (likely Wernicke-Korsakoff spectrum), necessitating lifelong higher-dose supplementation to prevent further deterioration 1, 2
Maintenance dosing after proven deficiency is 50-100mg daily: This applies to patients WITHOUT ongoing risk factors; your patient has persistent risk from AUD history 1
Specific Dosing Algorithm
For patients with AUD history plus established neurological complications:
- Continue 200-300mg daily orally indefinitely 1, 2
- This falls within the recommended range for alcoholic liver disease with neurological symptoms (100-300mg/day for 2-3 months minimum, but extended indefinitely when major NCD is present) 1
When 100mg would be appropriate (NOT your patient):
- Uncomplicated AUD without neurological sequelae after initial treatment phase 2
- Proven deficiency that has fully resolved in patients without malabsorption 1
- No ongoing risk factors for recurrent deficiency 1
Safety Considerations
- No toxicity concern: Thiamine has no established upper limit for toxicity; excess is excreted in urine 1
- Doses exceeding 400mg may cause mild nausea, anorexia, or ataxia, but 200mg is well below this threshold 1
- The benefit-risk ratio strongly favors continued supplementation in AUD patients with neurological damage 1
Monitoring Approach
- Check RBC or whole blood thiamine diphosphate (ThDP) levels every 6-12 months to confirm adequacy 1
- Monitor for progression of neurocognitive symptoms (worsening would indicate inadequate supplementation) 1
- Assess nutritional intake and alcohol use status at each visit 2
Critical Pitfall to Avoid
Never reduce thiamine in patients with both AUD history and established neurological damage—the major NCD indicates the brain has already sustained thiamine-deficiency injury and remains permanently vulnerable to further depletion 1, 2. Reducing to 100mg risks subclinical deficiency that could accelerate cognitive decline 3, 4.