Treatment of thiamine deficiency

Thiamine must be replaced. It is given IV or IM in a dose appropriate to the deficiency:

• mild chronic deficiency - 10-25 mg daily
• severe deficiency - 200-300 mg daily

Prevention and treatment of Wernicke's encephalopathy (1)

• treatment is urgent as once the amnesic syndrome - Korsakoff psychosis - is established
• only 50% of patients can be expected to show any improvement
• untreated, the condition is fatal
• offer thiamine to people at high risk of developing, or with suspected, Wernicke's encephalopathy. Thiamine should be given in doses toward the upper end of the 'British national formulary' range. It should be given orally or parenterally as follows:
  • offer prophylactic oral thiamine to harmful or dependent drinkers:
    • if they are malnourished or at risk of malnourishment or
    • if they have decompensated liver disease or
    • if they are in acute withdrawal or - before and during a planned medically assisted alcohol withdrawal
  • offer prophylactic parenteral thiamine followed by oral thiamine to harmful or dependent drinkers:
    • if they are malnourished or at risk of malnourishment or
    • if they have decompensated liver disease
    • and in addition
      • attend an emergency department or
      • are admitted to hospital with an acute illness or injury
  • offer parenteral thiamine to people with suspected Wernicke's encephalopathy. Maintain a high level of suspicion for the possibility of Wernicke's encephalopathy, particularly if the person is intoxicated. Parenteral thiamine should be given for a minimum of 5 days, unless Wernicke's encephalopathy is excluded. Oral thiamine should follow parenteral therapy
    • in the hospital setting
      • give intravenous thiamine 300 to 500mg three times a day for 3 to 5 days with daily review
      • if the individual is still symptomatic after 5 days of treatment, then give intravenous thiamine 300mg to 500mg once daily for a further 3 to 5 days for as long as clinical improvement continues
      • other causes for their confusion should be explored

Reference:

1. Berger MM, Shenkin A, Schweinlin A, et al. ESPEN micronutrient guideline. Clin Nutr. 2022 Jun;41(6):1357-424.