[Wernicke encephalopathy: Guiding thiamine prescription]

Wernicke's encephalopathy (WE) is a medical emergency. The objective of this paper is to systematically review the literature published over the past 15 years pertaining to prophylactic and curative treatment of WE with thiamine.

A systematic literature search was performed using Medline to include all studies published between January 1, 2000 and December 31, 2015.

Of the 316 abstracts identified, 20 met the final inclusion criteria. The evidence on the use of prophylactic thiamine was quite heterogeneous. The use of thiamine in this context largely depended on the evaluation of an individual's risk of developing WE. Use of prophylactic thiamine in low-risk patients is not universally indicated. When prescribed in this sub-population, the oral route is suggested but may be insufficient owing to its limited intestinal absorption and the high risk of non-compliance. High-risk patients need parenteral treatment with a recommended posology of 250 mg daily for 3 to 5 days. Intramuscular route is preferred in the outpatient setting, whereas intravenous route is suggested for inpatients. In cases where the diagnosis of WE is suspected or confirmed, a curative treatment with high-dose IV thiamine is justified. The evidence widely accepted in the literature is much clearer in this condition, with treatment regimens consisting of 500 mg IV 3 times daily for 3 to 5 days, followed by 250 mg IV daily for a minimum of 3 to 5 additional days.

The literature does indicate that thiamine should be prescribed at high dosages, with the parenteral routes indicated in hospital settings and in high-risk patients. Based on the current literature review, we suggest treatment algorithms guiding thiamine prescription for WE.