Initial Total Daily Insulin Dose for Pediatric Patients with Type 1 Diabetes

Calculation Method

The American Diabetes Association recommends an initial total daily dose of 0.5-1.0 units/kg for children with newly diagnosed type 1 diabetes, which for a 40kg child translates to 20-40 units per day 1, 2.
For a 40kg child, the lower end of the dose is calculated as 0.5 units/kg × 40kg = 20 units/day, and the upper end is 1.0 units/kg × 40kg = 40 units/day 1, 2.

The American Diabetes Association suggests starting at the lower end (0.5 units/kg = 20 units/day) if the child is younger or prepubertal, has no diabetic ketoacidosis (DKA) at presentation, and is metabolically stable 1, 2.
The American Diabetes Association recommends starting at the higher end (approaching 1.0 units/kg = 40 units/day) if the child presented with diabetic ketoacidosis, is on steroid therapy, or is pubertal or in puberty 1, 2.

The total daily dose should be divided approximately 50% basal and 50% prandial insulin, with basal insulin (long-acting) being 10 units once daily and prandial insulin (rapid-acting) being 10 units total, divided among three meals (approximately 3-4 units per meal) 2.

Infants and toddlers may require diluted insulin to allow precise 1-unit increment dosing, and insulin pens that deliver 0.5-unit increments are also available for young children 1, 2.
A "honeymoon phase" may occur within several weeks after starting insulin, where requirements may fall well below the initial 0.5-1.0 units/kg/day, and during this phase, children may require only minimal basal insulin with small amounts of rapid-acting insulin 1, 2.
Pubertal children may require insulin doses as high as 1.5 units/kg/day due to growth hormone and sex hormone effects, which for a 40kg pubertal child could mean up to 60 units/day 1, 2.