How Often Can You Increase Glargine Insulin
Increase glargine insulin by 2-4 units every 3 days until fasting blood glucose reaches 80-130 mg/dL, with the specific increment determined by your current fasting glucose level. 1
Standard Titration Algorithm
The American Diabetes Association provides a clear, evidence-based titration schedule based on fasting glucose readings 1:
- If fasting glucose is 140-179 mg/dL: Increase by 2 units every 3 days 1
- If fasting glucose is ≥180 mg/dL: Increase by 4 units every 3 days 1
- Target: Continue adjustments until fasting plasma glucose consistently reaches 80-130 mg/dL 1
This 3-day interval allows sufficient time to assess the effect of each dose change, as basal insulin reaches steady-state pharmacokinetics within this timeframe 1. The two components of your insulin regimen—basal (glargine) and correctional (sliding scale)—can be adjusted independently on their respective schedules, since correctional insulin addresses acute hyperglycemic excursions and does not accumulate to steady state 1.
Alternative Titration Approaches
Some guidelines suggest a percentage-based approach: increase the dose by 10-15% once or twice weekly until the fasting blood glucose target is met 1. This method may be particularly useful for patients on higher baseline doses where absolute unit increases become more substantial 1.
For patients with severe hyperglycemia (fasting glucose consistently >250 mg/dL), more aggressive titration with 4-unit increments every 3 days is appropriate to achieve glycemic targets faster 1.
Critical Threshold: When to Stop Escalating Basal Insulin
When your glargine dose exceeds 0.5 units/kg/day and approaches 1.0 units/kg/day, you should add prandial insulin rather than continuing to escalate basal insulin alone. 1 This threshold prevents "overbasalization"—a dangerous pattern where excessive basal insulin masks the need for mealtime coverage 1.
Clinical signals that you've reached this threshold include 1:
- Basal insulin dose >0.5 units/kg/day
- Bedtime-to-morning glucose differential ≥50 mg/dL
- Hypoglycemia episodes
- High glucose variability despite adequate fasting glucose control
At this point, further increases in glargine every 3 days may lead to overbasalization rather than improved glycemic control 1.
Safety Adjustments for Hypoglycemia
If hypoglycemia occurs without a clear cause, immediately reduce the glargine dose by 10-20% 1. Do not wait for the next scheduled adjustment interval—hypoglycemia requires immediate dose reduction 1.
If more than 2 fasting glucose values per week are <80 mg/dL, decrease the basal insulin dose by 2 units 1.
Special Considerations for Ultra-Long-Acting Insulins
For ultra-long-acting basal insulins (such as insulin degludec), some experts recommend waiting at least 1 week before making subsequent dose adjustments to fully assess glucose outcomes, as these formulations have longer pharmacokinetic profiles 1. However, for standard glargine (U-100), the 3-day interval remains appropriate 1.
Common Pitfalls to Avoid
Do not wait longer than 3 days between basal insulin adjustments in stable patients, as this unnecessarily prolongs the time to achieve glycemic targets 1. The danger of under-adjusting is demonstrated by the finding that 75% of hospitalized patients who experienced hypoglycemia had no basal insulin dose adjustment before the next administration 1.
Do not adjust glargine based on post-meal glucose readings—basal insulin is designed to control fasting and between-meal glucose levels, not postprandial hyperglycemia 1. If post-meal glucose remains elevated despite adequate fasting control, you need prandial insulin coverage, not more glargine 1.
Monitoring Requirements
Daily fasting blood glucose monitoring is essential during the titration phase 1. Check your fasting glucose every morning and adjust the dose accordingly based on the algorithm above 1. Reassess adequacy of insulin dose at every clinical visit, looking specifically for signs of overbasalization 1.