Insulin Administration Guidelines

Introduction to Insulin Administration

The American Diabetes Association recommends that the best time to administer insulin depends on the type of insulin and should coincide with meal times to maximize its effectiveness and minimize the risk of hypoglycemia 1

For NPH insulin, administration once a day is preferred at 20:00 hours, while twice a day administration should be before breakfast and before dinner 2
For long-acting insulin analogs (glargine, degludec), they can be administered at any time of day, maintaining a constant schedule, and glargine 300 and degludec do not require specific changes in timing 3
Administering insulin generally before breakfast and before dinner is recommended, with a typical distribution of 2/3 before breakfast and 1/3 before dinner 1

For patients who are eating, align insulin injections with meals 4
If oral intake is poor, administer prandial insulin immediately after the patient eats, adjusting the dose according to the amount consumed 4
Avoid prolonged use of insulin on a sliding scale as the only treatment 4

Administer the basal insulin subcutaneous dose 2 hours before discontinuing intravenous infusion 4
The basal dose should be calculated based on the infusion rate during the last 6 hours when stable glucose targets were achieved 4

Titrate based on fasting glucose readings over a week, increasing by 2 units if 50% of fasting values are above target, and decreasing by 2 units if more than 2 fasting values per week are below 80 mg/dL 5
Generally, administer a dose with the largest meal or the meal with the greatest postprandial glucose excursion, with an initial dose of 4 units per day or 10% of the basal insulin dose, and increase the dose by 1-2 units or 10-15% as needed 1

Do not mix insulin glargine with other forms of insulin due to its low pH diluent, and do not mix phosphate-buffered insulins (such as NPH) with lente insulins 6
Failing to provide basal insulin before discontinuing intravenous infusion can lead to rebound hyperglycemia 4

Reconnect the personal insulin pump as soon as the patient can manage it autonomously, and if the patient is not autonomous, initiate a basal-bolus regimen via immediate subcutaneous injection 2