Insulin Administration Frequency
Insulin can be administered multiple times per day depending on the regimen, with basal insulin typically given once or twice daily and prandial insulin administered before each meal (up to 3–4 times daily), plus correction doses as needed.
Basal Insulin Dosing Frequency
Long-acting basal insulin analogs (glargine, detemir, degludec) are typically administered once daily at the same time each day, though some patients may require twice-daily dosing for adequate 24-hour coverage 1, 2.
Insulin glargine can be given at any time of day but must be administered at the same time every day to maintain stable basal insulin levels 2, 3.
In patients with type 1 diabetes experiencing high glycemic variability or inadequate 24-hour coverage, insulin glargine may require twice-daily administration rather than once daily 4, 3.
NPH insulin is typically given 2–3 times daily (every 8–12 hours) to cover basal and nutritional needs, particularly in patients receiving enteral/parenteral nutrition 1.
Prandial (Mealtime) Insulin Frequency
Rapid-acting insulin analogs (lispro, aspart, glulisine) are administered 0–15 minutes before each meal, typically 3 times daily with breakfast, lunch, and dinner 1.
Regular human insulin can be given before meals but requires administration 30–45 minutes prior to eating, making it less flexible than rapid-acting analogs 4, 5.
In hospitalized patients eating regular meals, prandial insulin should be given before each of the three main meals (3 times daily) 1, 4.
Correction (Supplemental) Insulin Frequency
Correction insulin using rapid-acting analogs can be administered every 4 hours when needed for hyperglycemia 1.
Regular human insulin for correction doses should be given subcutaneously every 6 hours in hospitalized patients 1.
Point-of-care glucose should be checked before each meal and at bedtime (minimum 4 times daily) to guide correction dosing 1, 4.
Special Clinical Situations
Continuous Enteral/Parenteral Nutrition
For patients on continuous tube feeding, NPH insulin is given every 8–12 hours or regular insulin every 6 hours to cover the continuous carbohydrate load 1.
Basal insulin must be continued even if enteral nutrition is interrupted to prevent hyperglycemia and ketosis in insulin-dependent patients 1.
Glucocorticoid Therapy
NPH insulin is typically administered 2–3 times daily (every 8–12 hours) when patients are on intermediate-acting steroids like prednisone 1.
Morning NPH dosing is specifically recommended to align with the steroid's peak hyperglycemic effect occurring 4–12 hours after morning prednisone 1.
Hospitalized Patients (Non-Critical Care)
Basal insulin is given once daily, with prandial insulin before each of the three main meals (total of 4 injections daily in a basal-bolus regimen) 1, 4.
For patients with poor oral intake or NPO status, glucose should be checked every 4–6 hours with correction insulin as needed 1, 4.
Maximum Daily Injection Frequency
In intensive insulin therapy for type 1 diabetes, patients may require 4–6 injections daily: one basal injection plus 3 prandial injections, with additional correction doses as needed 4, 5.
Patients on insulin pump therapy receive continuous basal insulin infusion with bolus doses before meals, eliminating the need for multiple daily injections 4.
Critical Safety Considerations
Never administer rapid-acting insulin at bedtime as a sole correction dose, as this markedly increases nocturnal hypoglycemia risk 1, 4.
Sliding-scale insulin should never be used as monotherapy; it must supplement a scheduled basal-bolus regimen 1, 4.
Basal insulin must never be completely withheld in insulin-dependent patients, even when NPO, to prevent diabetic ketoacidosis 1, 4.