Why Thiamine before Glucose in Wernicke Encephalopathy?

The proposed mechanism for this is as follows:

• Thiamine 100mg IV before 50% glucose
• Thiamine is an important co-enzyme for carbohydrate utilization as (thiamine pyrophosphate- TPP)
• Therefore TTP is required to convert pyruvate to Acetyl-CoA. To put it another way, if you’re thiamine deficient, any glucose you get will tend to form lactate, rather than being fully metabolized in the Krebs Cycle [1]

References

1. Hoyumpa AM, Jr. Mechanisms of thiamin deficiency in chronic alcoholism.  Am J Clin Nutr  1980;33:2750-2761.