Thiamine

Thiamine is first-line therapy for confirmed B1 deficiency in patients with chronic alcoholism, after bariatric surgery, with malabsorption syndromes or prolonged inadequate nutrition. AEMPS registers Benerva 300 mg tablets and parenteral formulations. For dry and wet beriberi the dose is 100-300 mg/day orally for 1-2 weeks then maintenance 25-50 mg/day. WHO 2018 underlines: in at-risk patients with suspected deficiency, give thiamine BEFORE the first glucose infusion, otherwise the glucose load precipitates Wernicke encephalopathy.

Parenteral thiamine is the cornerstone of acute Wernicke encephalopathy treatment. EFNS and the Royal College of Physicians recommend thiamine 500 mg IV three times daily for 2-3 days, then 250 mg/day IV or IM for 5-7 days, followed by oral maintenance. Oral 300 mg tablets give inadequate bioavailability in acute Wernicke – parenteral route is required. The UK uses Pabrinex (thiamine plus other B vitamins) IV on a similar schedule. Cochrane 2013 acknowledges scarce high-quality RCTs but clinical practice and physiological data give thiamine emergency-treatment status.