Insulin Glargine Titration for Hyperglycemia
Increase insulin glargine by 2 units every 3 days when fasting glucose is 140-179 mg/dL, or by 4 units every 3 days when fasting glucose is ≥180 mg/dL, until reaching a target fasting glucose of 80-130 mg/dL. 1
Standard Titration Algorithm
The American Diabetes Association provides a clear, evidence-based approach for adjusting basal insulin 1:
- Start with 10 units daily or 0.1-0.2 units/kg/day for insulin-naive patients 1, 2
- Set your fasting plasma glucose goal at 80-130 mg/dL 1
- Adjust every 3 days based on fasting glucose readings 1, 2:
- For hypoglycemia without clear cause: immediately reduce dose by 10-20% 1, 2
This 3-day interval allows sufficient time to assess the effect of dose changes while avoiding unnecessarily prolonged time to glycemic targets 2. Research supports that both weight-based titration (0.1 units/kg increments daily) and glucose-based titration (2-8 unit increments) are effective, with the glucose-based approach being simpler and equally safe 3.
Alternative Patient-Driven Titration
For motivated patients capable of self-management, a more aggressive approach increases the dose by 1 unit daily when fasting glucose exceeds 5.5 mmol/L (99 mg/dL) 4, 5. This patient-driven algorithm achieves glycemic targets faster without increasing hypoglycemia risk and is preferred by 86% of healthcare professionals 5. The INSIGHT algorithm demonstrated that daily 1-unit increases with the target of 4.4-5.6 mmol/L (79-101 mg/dL) was as safe as the standard every-3-day approach 5.
Alternative Percentage-Based Titration
Increase by 10-15% of the current dose once or twice weekly until fasting glucose reaches target 1, 2. This approach is particularly useful when doses become higher, as a fixed 2-4 unit increase may be insufficient 2.
Critical Threshold: When to Stop Escalating Basal Insulin
Stop increasing glargine when the dose exceeds 0.5 units/kg/day and consider adding prandial insulin or a GLP-1 receptor agonist instead 1, 2. Continuing to escalate basal insulin beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia leads to "overbasalization"—a dangerous pattern causing hypoglycemia and high glucose variability 2.
Clinical Signs of Overbasalization 2:
- Basal insulin dose >0.5 units/kg/day
- Bedtime-to-morning glucose differential ≥50 mg/dL
- Hypoglycemia (aware or unaware)
- High glucose variability
- A1C remains elevated despite controlled fasting glucose
When these signs appear, add 4 units of rapid-acting insulin before the largest meal (or 10% of current basal dose) rather than continuing to increase glargine 1, 2.
Monitoring Requirements
- Daily fasting blood glucose monitoring is essential during active titration 2
- Reassess at every clinical visit for signs of overbasalization 1, 2
- If more than 2 fasting values per week are <80 mg/dL: decrease dose by 2 units 2, 6
Special Populations Requiring Modified Approaches
Hospitalized Patients
For hospitalized patients who are insulin-naive or on low-dose insulin, start with 0.3-0.5 units/kg/day total daily dose, giving half as basal insulin 2. For patients on high-dose home insulin (≥0.6 units/kg/day), reduce the total daily dose by 20% upon hospitalization to prevent hypoglycemia 2.
Severe Hyperglycemia
For patients with blood glucose ≥300-350 mg/dL and/or A1C ≥10-12% with symptomatic or catabolic features, start with basal-bolus insulin immediately rather than basal insulin alone, using 0.3-0.5 units/kg/day as total daily dose 2.
High-Risk Patients
For elderly patients (>65 years), those with renal failure, or poor oral intake, use lower doses (0.1-0.25 units/kg/day) 2.
Common Pitfalls to Avoid
- Waiting longer than 3 days between adjustments in stable patients unnecessarily prolongs time to glycemic targets 2
- Continuing to escalate basal insulin beyond 0.5 units/kg/day without adding prandial coverage leads to overbasalization 1, 2
- Not reducing the dose after hypoglycemia: 75% of hospitalized patients who experienced hypoglycemia had no dose adjustment before the next administration 2
- Stopping metformin when adding insulin: metformin should be continued unless contraindicated 2