Insulin Glargine (Lantus) Titration Guidelines

Standard Titration Algorithm

Increase the basal insulin dose by 2 units every 3 days when fasting glucose is 140–179 mg/dL; increase by 4 units every 3 days when fasting glucose is ≥180 mg/dL, aiming for a fasting target of 80–130 mg/dL. 1
If an unexplained hypoglycemic episode occurs (glucose < 70 mg/dL), reduce the current dose by 10–20 % immediately. 1
Continue dose adjustments until fasting glucose consistently falls within the target range, and perform daily fasting glucose checks throughout the titration phase. 1

When basal insulin exceeds 0.5 units/kg/day and approaches 1.0 units/kg/day, add rapid‑acting (prandial) insulin rather than further increasing basal insulin. 1
Over‑basalization is characterized by increased hypoglycemia risk without further improvement in overall glycemic control. 1
Clinical clues of over‑basalization include:
Add 4 units of rapid‑acting insulin (or ≈10 % of the basal dose) before the largest meal, then titrate the prandial dose by 1–2 units every 3 days based on post‑prandial glucose readings. 1

Patients should measure fasting glucose each morning and record the values to guide dose changes every 3 days. 1
Apply the standard titration rules (2 U or 4 U increments) according to the fasting glucose pattern. 1
Contact a healthcare professional if any of the following occur:

For individuals with HbA1c ≥ 9 % or fasting glucose ≥ 300–350 mg/dL, start Lantus at 0.3–0.4 units/kg/day. 1

Once‑daily administration at the same time each day is recommended; the exact time (morning, evening, or bedtime) should be chosen for patient convenience but must remain consistent. 1
In select cases (e.g., type 1 diabetes with high glycemic variability or persistent nocturnal hypoglycemia with morning hyperglycemia), split the total daily dose into two equal injections 12 hours apart to achieve more reliable 24‑hour coverage. 1

Do not continue escalating basal insulin beyond 0.5–1.0 units/kg/day without addressing post‑prandial hyperglycemia, as this leads to over‑basalization and higher hypoglycemia risk. 1
Do not discontinue metformin when initiating or increasing basal insulin unless contraindicated; the combination yields superior glycemic control, lowers insulin requirements, and mitigates weight gain. 1
Do not use sliding‑scale insulin as monotherapy while titrating basal insulin; major diabetes guidelines advise against this practice because it causes erratic glucose fluctuations. 1

Every 3 days during active titration to adjust dose based on fasting glucose trends. 1
Every 3–6 months once the regimen is stable to review overall glycemic control and HbA1c. 1
If HbA1c remains above target after 3–6 months despite achieving fasting glucose goals, consider adding prandial insulin. 1

Maintain metformin at the maximum tolerated dose (up to ~2,500 mg daily) while titrating Lantus, unless contraindicated. 1