Thiamine before glucose? A myth that has long been debunked

April 18, 2012, 12:14 am

★★★☆☆

Glucose Before Thiamine for Wernicke Encephalopathy: A Literature Review. Schabelman E, Kuo D. J Emerg Med 2012 Apr;42:488-494.

Abstract

It had been an axiom long taught on medicine wards that before malnourished patients — especially alcoholics — are given intravenous glucose, they must first receive parenteral thiamine. The fear was that in the process of metabolizing the glucose a marginal thiamine deficiency would be turned into a complete thiamine deficiency, precipitating the devastating and often persistent neurological conditions Wernicke’s encephalopathy and Korsakoff syndrome.

There is no clinical or experimental evidence to support this belief, and it has been thoroughly debunked at least since the appearance of an important article by Hack and Hoffman in 1998 (JAMA 1998;279:583-4). The authors review the literature related to this question — not especially clearly, I’m afraid — and come to the proper conclusion:

Patients with hypoglycemia should be restored to normoglycemia as quickly as possible (repeated dosing of dextrose 50% in adults until normoglycemia is achieved).

All patients at risk for malnutrition should be given thiamine intravenously or intramuscularly as soon as possible after restoration of normoglycemia . . .”

Note that patients at risk for malnutrition and thiamine deficiency include not only alcoholics, but also those with malignancies, hyperemesis gravidarum, AIDS, and anorexia/bulimia, among others.

To read my 2007 Emergency Medicine News column on this same issue — referenced in this paper but not evaluated in the literature review — click here.

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