When to Decrease Lantus (Insulin Glargine)
Decrease Lantus by 2 units if more than two fasting blood glucose values per week are less than 80 mg/dL (4.4 mmol/L), and reduce the dose by 10-20% immediately if hypoglycemia occurs without a clear cause. 1
Immediate Dose Reduction Scenarios
Hypoglycemia-Related Reductions
- Reduce Lantus by 10-20% immediately if any episode of severe hypoglycemia occurs 1
- Decrease by 2 units when more than 2 fasting glucose values per week fall below 80 mg/dL 1
- If hypoglycemia occurs without clear cause (missed meal, unusual exercise, medication error), reduce dose by 10-20% before the next administration 1
High-Risk Patient Populations Requiring Lower Doses
- Hospitalized patients on high-dose home insulin (≥0.6 units/kg/day) should have their total daily dose reduced by 20% upon admission to prevent hypoglycemia 1
- Elderly patients (>65 years), those with renal failure, or poor oral intake require lower doses (0.1-0.25 units/kg/day) 1
- Patients with acute illness and poor oral intake need dose reduction to avoid hypoglycemia risk 1
Renal Impairment Considerations
- For patients with CKD Stage 5 and type 2 diabetes, reduce total daily insulin dose by 50% 1
- For type 1 diabetes patients with CKD Stage 5, reduce total daily insulin dose by 35-40% 1
- Insulin clearance decreases with declining kidney function, requiring closer monitoring and dose adjustments 1
Clinical Situations Requiring Dose Reduction
Perioperative Management
- Reduce insulin dose by approximately 25% the evening before surgery to achieve target glucose levels with decreased hypoglycemia risk 1
Poor Oral Intake or NPO Status
- Immediately reduce total daily insulin to 0.1-0.15 units/kg/day given primarily as basal insulin in patients with decreased oral intake 1
- Reduce total daily insulin by 50% in patients with poor oral intake to prevent severe hypoglycemia 1
Signs of Overbasalization
When basal insulin exceeds 0.5 units/kg/day without achieving glycemic targets, do not continue increasing Lantus—instead add prandial insulin or a GLP-1 receptor agonist 1. Clinical signals of overbasalization include:
- Basal dose >0.5 units/kg/day 1
- Bedtime-to-morning glucose differential ≥50 mg/dL 1
- Recurrent hypoglycemia 1
- High glucose variability 1
Monitoring Requirements During Dose Reduction
- Check fasting blood glucose daily during dose adjustments 1
- Reassess adequacy of insulin dose at every clinical visit 1
- Monitor for hypoglycemia more frequently (every 4-6 hours) in high-risk patients with poor oral intake 1
Common Pitfalls to Avoid
- Do not delay dose reduction when hypoglycemia occurs—75% of hospitalized patients who experienced hypoglycemia had no basal insulin dose adjustment before the next administration 1
- Avoid continuing the same dose in patients with declining renal function, as insulin clearance decreases significantly 1
- Do not maintain high doses (>0.5 units/kg/day) when signs of overbasalization are present 1