DRUG SUPPLIED DOSE COMMENTS
THIAMINE (Paeds)
(Vitamin B1)

Mechanism of action:

Vitamin B1



Ref: 44,  62, 649, 723, 724


Last update: 2025-10-19
tablet:   50 mg, 100 mg
liquid (BCCH):
100 mg/mL
injection:
100 mg/mL
Patients at risk of Refeeding Syndrome:
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

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.



Standard Prescription:

thiamine__mg PO{IM/IV}__(frequency)