Traditionally the treatment dose of thiamine in those that we suspect to have Wernicke's Encephalopathy is 100mg per day. The problem is that this does was arbiarily picked by two physicians, Victor and Adams, in the 1950's. They thought that 100mg a day would be a large dose. They also made their recommendation without fully understanding the pharmacokinetics of thiamine which has a half life of 96 minutes or less. Compound this with case reports of individuals dying of Wernike's Encephalopathy despite being given 100mg of Thiamine daily.
Several authors are now advocating that patients with Wernicke's Encephalopathy be treated with 500mg of IV thiamine daily, but with the short half life some are advocating that the thiamine be given 2 to 3 times a day. There are no good studies to refute or support the claims that higher doses are needed, but there are well documented cases of treatment failures at the lower dose.
PEARLs:
Consider high dose thiamine 500mg IV in patients that you are treating with Wernike's encephalopathy.
The 100mg dose is still appropriate for those that are just being suppliemented and in who Wernicke's encephalopathy is a consideation but not high up on the differential.
References
Donnino MW, Vega J, Miller J, Walsh M. Myths and misconceptions of Wernicke's encephalopathy: what every emergency physician should know. Ann Emerg Med. Dec 2007;50(6):715-721.
