Indicated for: vitamin deficiency
Route of administration: oral
Substance: thiamine (vitamin)
ATC: A11DA01 (Alimentary tract and metabolism | Vitamin B1, plain and in combination with vitamin B6 and B12)
Thiamine, also called vitamin B1, is an essential vitamin needed to turn food into energy and to support the normal function of nerves, muscles and the heart. As a medicine, it is used to prevent or treat thiamine deficiency, including beriberi and Wernicke encephalopathy, a neurological emergency linked to malnutrition, prolonged vomiting or heavy alcohol use.
Thiamine may be given by mouth, by intramuscular injection or intravenously, depending on how severe the deficiency is. Mild cases may be treated with tablets, while suspected neurological involvement may require urgent injectable treatment. The dose and duration depend on the cause of deficiency, diet, associated illnesses and the patient’s clinical response.
Thiamine deficiency can cause tiredness, irritability, loss of appetite, tingling, numbness, muscle weakness, unsteady walking, confusion, memory problems, abnormal eye movements, palpitations or leg swelling. Treatment is usually well tolerated. Side effects are uncommon but may include nausea, discomfort after injection or allergic reactions.
Seek urgent medical help if confusion, severe sleepiness, visual disturbance, marked weakness, breathing difficulty or swelling occurs. People with alcohol dependence, bariatric surgery, malabsorption, dialysis, very restrictive diets or persistent vomiting are at higher risk. Timely thiamine treatment can prevent severe and sometimes permanent neurological complications.