Overview
Thiamine (Vitamin B1) is an essential water-soluble vitamin that functions as a coenzyme in carbohydrate metabolism and energy production. It is used to treat and prevent thiamine deficiency, including conditions like beriberi and Wernicke-Korsakoff syndrome. Thiamine is generally well-tolerated with minimal toxicity.
Mechanism of Action
Thiamine acts as a coenzyme (thiamine pyrophosphate) in carbohydrate metabolism, facilitating decarboxylation of alpha-keto acids and transketolation in the pentose phosphate pathway. It is essential for energy production, nerve conduction, and myocardial function.
Indications
- Treatment and prevention of thiamine deficiency (beriberi)
- Wernicke-Korsakoff syndrome
- Metabolic disorders requiring thiamine supplementation
- Alcohol use disorder with nutritional deficiency
Common Doses
- 50 mg tablet
- 100 mg tablet
- 100 mg/mL injection
- 250 mg/mL injection
Dosage
Typical adult dosage for deficiency: 5-30 mg daily in divided doses; for severe deficiency (Wernicke's encephalopathy): 100 mg IV initially, then 50-100 mg IM/IV daily until clinical improvement. Maintenance: 5-10 mg daily orally.
Contraindications
- Known hypersensitivity to thiamine or any component of the formulation
Side Effects
- Generally well-tolerated
- Rare hypersensitivity reactions (itching, urticaria, anaphylaxis)
- Local irritation with parenteral administration
- Nausea at high oral doses
Interactions
- Loop diuretics (furosemide) may increase thiamine excretion
- Chronic alcohol use impairs thiamine absorption and utilization
Counseling Points
- Take with food to minimize gastrointestinal upset
- Do not exceed recommended dosage without medical supervision
- Store in a cool, dry place away from light and moisture
- Inform healthcare provider if pregnant, planning pregnancy, or breastfeeding