Q: Why it is advisable to give parenteral administration (IV or IM) of thiamine to prevent wernicke encephalopathy (WE) in patients presented with alcohol intoxication or severe malnourishment?



Answer: 

Three things should be considered while giving thiamine to prevent WE.

1. Gastrointestinal (GI) absorption of thiamine is erratic, particularly in alcoholic and malnourished patients.

2.  Thiamine should be given before glucose, as glucose without thiamine can precipitate or worsen WE.

3. Some patients have genetically determined requirement for much higher doses of thiamine. As thiamine is safe, cheap in cost, and very effective, there is usually no harm to stay towards higher side of dosing.



 References: 

1. Galvin R, Bråthen G, Ivashynka A, et al. EFNS guidelines for diagnosis, therapy and prevention of Wernicke encephalopathy. Eur J Neurol 2010; 17:1408. 

2. Wrenn KD, Murphy F, Slovis CM. A toxicity study of parenteral thiamine hydrochloride. Ann Emerg Med 1989; 18:867. 

3. Agabio R. Thiamine administration in alcohol-dependent patients. Alcohol Alcohol 2005; 40:155.

4. Thomson AD, Cook CC, Touquet R, et al. The Royal College of Physicians report on alcohol: guidelines for managing Wernicke's encephalopathy in the accident and Emergency Department. Alcohol Alcohol 2002; 37:513. 

5. Day E, Bentham P, Callaghan R, et al. Thiamine for Wernicke-Korsakoff Syndrome in people at risk from alcohol abuse.