Continue Insulin Glargine in the Hospital
For a patient taking 15 units of insulin glargine each morning at home, continue insulin glargine (or detemir) as the basal insulin in the hospital, administered once daily at the same time. 1
Recommended Approach
Basal Insulin Selection and Dosing
The Endocrine Society guidelines explicitly state that basal insulin should be given once daily with glargine or detemir in hospitalized patients 1. For your patient:
- Continue glargine 15 units once daily in the morning (same timing as home regimen)
- Glargine and detemir are the preferred long-acting basal insulins for hospital use
- NPH is an alternative but requires twice-daily dosing and has a peak action that increases hypoglycemia risk 1
Dose Adjustment Considerations
Do NOT automatically reduce the home basal insulin dose unless specific risk factors are present 1:
Reduce dose by 10-20% if:
- Age ≥70 years
- GFR <60 mL/min
- Poor oral intake expected
- Admission blood glucose <100 mg/dL 1
For patients on higher home doses (≥0.6 U/kg/day): Consider 20% reduction to prevent hypoglycemia with poor oral intake 2
For this patient on 15 units: This is a relatively low dose, so unless the above risk factors apply, continue the full 15 units.
Complete Hospital Insulin Regimen
The basal insulin alone is insufficient. All patients on home insulin require scheduled subcutaneous insulin in the hospital, not sliding scale insulin (SSI) alone 1:
If Patient Is Eating:
- Basal insulin: Glargine 15 units once daily (morning)
- Prandial insulin: Add rapid-acting insulin (lispro, aspart, or glulisine) before each meal
- Correction insulin: Supplemental rapid-acting insulin for blood glucose >140 mg/dL 1
If Patient Is NPO (Nothing by Mouth):
- Basal insulin: Continue glargine 15 units once daily
- Hold prandial insulin until eating resumes
- Correction insulin only: Rapid-acting analog every 4 hours OR regular insulin every 6 hours 1
Critical Pitfalls to Avoid
Never discontinue basal insulin in hospitalized patients, especially those with type 1 diabetes—this can rapidly lead to diabetic ketoacidosis 1, 3. Even when NPO, basal insulin must continue 1.
Avoid SSI as sole therapy—this outdated practice increases hyperglycemia risk 3-fold and results in poor glycemic control 1. SSI should only supplement scheduled basal-bolus regimens.
Do not switch to NPH unless there's a specific indication (e.g., steroid-induced hyperglycemia) 4. Glargine/detemir have more predictable absorption, no peak action, and lower hypoglycemia risk compared to NPH 1.
Timing Flexibility
While your patient takes glargine in the morning at home, glargine can be administered at any consistent time in the hospital (morning, evening, or bedtime) with similar efficacy 5, 6. However, maintaining the home timing (morning) is reasonable for continuity and may facilitate discharge planning.