What is the recommended starting dose of Lantus (insulin glargine) for a patient with type 1 or type 2 diabetes?

Lantus (Insulin Glargine) Dosing

Starting Dose for Type 2 Diabetes

For insulin-naive patients with type 2 diabetes, start Lantus at 10 units once daily OR 0.1-0.2 units/kg body weight, administered at the same time each day. 1, 2, 3

• The FDA-approved starting dose is 0.2 units/kg or up to 10 units once daily 3
• Continue metformin (unless contraindicated) and possibly one additional non-insulin agent when initiating basal insulin 1
• For patients with severe hyperglycemia (HbA1c ≥9%, blood glucose ≥300-350 mg/dL), consider higher starting doses of 0.3-0.5 units/kg/day as total daily insulin using a basal-bolus regimen from the outset 1

Starting Dose for Type 1 Diabetes

For type 1 diabetes, the recommended starting dose is approximately one-third of total daily insulin requirements (typically 0.4-1.0 units/kg/day total insulin), with Lantus providing the basal component. 2, 3

• For metabolically stable patients, start with 0.5 units/kg/day total insulin, giving approximately 50% as Lantus (basal) and 50% as rapid-acting insulin (prandial) divided among meals 1, 2
• Higher doses are required immediately following diabetic ketoacidosis presentation 2
• Lantus must be used concomitantly with short-acting insulin in type 1 diabetes 3

Dose Titration Algorithm

Increase Lantus by 2-4 units every 3 days until fasting blood glucose reaches 80-130 mg/dL (4.4-7.2 mmol/L). 1, 4

• 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, 4
• If hypoglycemia occurs without clear cause: reduce dose by 10-20% immediately 1, 4
• If more than 2 fasting values per week are <80 mg/dL: decrease dose by 2 units 1, 4

Critical Dosing Threshold: When to Stop Escalating Basal Insulin

When Lantus exceeds 0.5 units/kg/day and approaches 1.0 units/kg/day, add prandial insulin rather than continuing to escalate basal insulin alone. 1, 4

• Clinical signals of "overbasalization" include: basal dose >0.5 units/kg/day, bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia episodes, and high glucose variability 1
• Start prandial insulin with 4 units of rapid-acting insulin before the largest meal, or use 10% of current basal dose 1
• Continuing to escalate basal insulin beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia leads to suboptimal control and increased hypoglycemia risk 1, 4

Administration Guidelines

Administer Lantus subcutaneously once daily at the same time each day into the abdominal area, thigh, or deltoid. 3

• Rotate injection sites within the same region to reduce risk of lipodystrophy 3
• Do not administer intravenously or via insulin pump 3
• Do not dilute or mix Lantus with any other insulin or solution 3
• Lantus can be given at any time of day, but consistency in timing is essential 1

Monitoring Requirements

Daily fasting blood glucose monitoring is essential during the titration phase. 1, 4

• Reassess every 3 days during active titration 1, 4
• Reassess every 3-6 months once stable 1, 4
• Increase frequency of blood glucose monitoring during any changes to insulin regimen 3

Common Pitfalls to Avoid

• Never delay insulin initiation in patients not achieving glycemic goals with oral medications 1
• Never discontinue metformin when starting insulin unless contraindicated 1
• Never continue escalating basal insulin beyond 0.5-1.0 units/kg/day without adding prandial coverage 1, 4
• Avoid injecting into areas of lipodystrophy, as this can cause hyperglycemia 3