Calculating the Dose for Long-Acting Insulin BID

Initial Dosing Algorithm

The American Diabetes Association recommends starting with 0.1-0.2 units/kg/day total, split evenly between morning and evening doses for long-acting insulin administered twice daily (BID) 1
For patients already on insulin, consider a 20% reduction in total daily dose when transitioning from another regimen to prevent hypoglycemia, as suggested by The Lancet Diabetes and Endocrinology 2
The total daily dose should be divided equally between morning and evening doses, according to The Lancet Diabetes and Endocrinology 2
For example, for a 70kg insulin-naive patient, the total daily dose would be 7-14 units, giving 3.5-7 units in the morning and 3.5-7 units in the evening, as recommended by Diabetes Care 1

Set a fasting plasma glucose (FPG) goal based on individual patient factors, as recommended by Diabetes Care 1
Adjust the dose by 2 units every 3 days until the FPG goal is reached without hypoglycemia, according to Diabetes Care 1
If hypoglycemia occurs, determine the cause and reduce the dose by 10-20% if no clear reason is identified, as suggested by Diabetes Care 1

For elderly patients or those with renal impairment, start with lower doses (0.1 units/kg/day) to minimize hypoglycemia risk, as recommended by The Lancet Diabetes and Endocrinology 2
For patients on glucocorticoids, consider administering NPH insulin in the morning to counteract steroid-induced daytime hyperglycemia, according to Diabetes Care 1
For patients with higher insulin requirements (≥0.6 units/kg/day), consider splitting the total daily dose with approximately 50-60% as basal insulin and 40-50% as prandial insulin, as suggested by Diabetes Care 4

Assess the adequacy of the insulin dose at every visit, as recommended by Diabetes Care 1
Monitor for clinical signs of overbasalization, including elevated bedtime-to-morning glucose differential, hypoglycemia, or high glucose variability, according to Diabetes Care 1
For patients with type 1 diabetes, total daily insulin requirements typically range from 0.4 to 1.0 units/kg/day, with approximately 50% as basal insulin, as suggested by Diabetes Care 4

Avoid using sliding scale insulin alone, especially in type 1 diabetes patients, as recommended by The Lancet Diabetes and Endocrinology 6
Do not use premixed insulin therapy in hospital settings due to the high risk of hypoglycemia, according to The Lancet Diabetes and Endocrinology 6
When transitioning from IV to subcutaneous insulin, ensure overlap to prevent rebound hyperglycemia, as suggested by The Lancet Diabetes and Endocrinology 6
Remember that insulin requirements may increase during puberty, menses, and medical illness, according to Diabetes Care 4