Thiamine (Vitamin B1)

- 30mg/ml and 200mg/2ml vials (IV, IM)

- 10, 50, 100 and 250mg tablets (PO)

Emergency Medicine Executive Summary

(Updated November 2022)

Thiamine (vitamin B1) is a water-soluble vitamin that is essential in the creation and utilization of cellular energy related to aerobic glycolysis in the citric acid cycle (1, 4). Its deficiency leads to cardiovascular (heart failure) and neurologic disease (Wernicke - Korsakoff syndrome, "WK"). In the ED thiamine is frequently indicated in the prevention and treatment of WK, mainly in patients with ethanol dependence and/or malnutrition (1).

Adult dose for WK treatment

    • 500mg IV every 8 hours for 3-5 days, then 250mg IV daily for 3-5 days, then indefinitely PO supplementation

    • Consider magnesium supplementation (2gr MgSO4 daily)

Adult dose

Adult dose for WK prevention and treatment (1, 2, 3, 4)

  • WK prevention

    • 250mg IV daily for 3-5 days, then 100mg PO daily

  • WK treatment

    • 500mg IV every 8 hours for 3-5 days, then 250mg IV daily for 3-5 days, then indefinitely PO supplementation

    • Consider magnesium supplementation (2gr MgSO4 daily)


  1. Thomson AD, Cook CC, Touquet R, Henry JA; Royal College of Physicians, London. The Royal College of Physicians report on alcohol: guidelines for managing Wernicke's encephalopathy in the accident and Emergency Department [published correction appears in Alcohol Alcohol. 2003 May-Jun;38(3):291]. Alcohol Alcohol. 2002;37(6):513-521. doi:10.1093/alcalc/37.6.513

  2. Lingford-Hughes AR, Welch S, Peters L, Nutt DJ; British Association for Psychopharmacology, Expert Reviewers Group. BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP. J Psychopharmacol. 2012;26(7):899-952. doi:10.1177/0269881112444324

  3. Boulanger AS, Paquette I, Létourneau G, Richard-Devantoy S. Thiamine et encéphalopathie de Gayet-Wernicke : quelles règles de prescription ? [Wernicke encephalopathy: Guiding thiamine prescription]. Encephale. 2017;43(3):259-267. doi:10.1016/j.encep.2016.04.011

  4. Nelson LS, Howland MA, Lewin NA, et al. Goldfrank’s Toxicologic Emergencies. 11th edition. New York, NY: McGraw-Hill Education; 2019.

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