THIAMINE
(Vitamin B1)Standard Prescription
thiamine__mg PO{IM/IV}__(frequency)
Dosages
Patients at risk of Refeeding Syndrome:
*continue for 5-7 days, or longer if severe starvation, chronic alcoholism or other high risk of deficiency +/- signs of thiamine deficiency
Severe Deficiency, treatment:
Infant: 25-50 mg IV once, then 10 mg IM daily x 1 week, then 3-5 mg PO daily x at least 6 weeks
Child: 10-25 mg IM/IV daily x 1-2 weeks , then 5-10 mg PO daily x at least 6 weeks
Adolescents: 100 mg IV/IM daily x up to 7 days (if critically ill), then 10 mg PO once daily
Child: 2 mg/kg/dose PO/IV/IM daily.
Maximum: 200 mg/24h
Adult: 100 mg PO/IV/IM daily*continue for 5-7 days, or longer if severe starvation, chronic alcoholism or other high risk of deficiency +/- signs of thiamine deficiency
Severe Deficiency, treatment:
Infant: 25-50 mg IV once, then 10 mg IM daily x 1 week, then 3-5 mg PO daily x at least 6 weeks
Child: 10-25 mg IM/IV daily x 1-2 weeks , then 5-10 mg PO daily x at least 6 weeks
Adolescents: 100 mg IV/IM daily x up to 7 days (if critically ill), then 10 mg PO once daily
Mechanism of Action
Vitamin B1
Forms Supplied
tablet: 50 mg, 100 mg
liquid (BCCH): 100 mg/mL
injection: 100 mg/mL
liquid (BCCH): 100 mg/mL
injection: 100 mg/mL
Comments
Parenteral administration is preferred in critically ill patients.
Higher doses may be required in Wernicke’s encephalopathy (up to 500 mg IV TID) and metabolic disorders such as Maple Syrup disease.
Start thiamine promptly if deficiency suspected.
Start thiamine prior to initiating feeding or dextrose-containing IV fluid if at risk of refeeding syndrome.
Higher doses may be required in Wernicke’s encephalopathy (up to 500 mg IV TID) and metabolic disorders such as Maple Syrup disease.
Start thiamine promptly if deficiency suspected.
Start thiamine prior to initiating feeding or dextrose-containing IV fluid if at risk of refeeding syndrome.
References
44, 62, 649, 723, 724
Last Edited
2025-10-19 00:05:20