What is the recommended starting dose of Lantus (insulin glargine) for a patient initiating therapy?

Lantus Starting Dose

For insulin-naïve 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, and titrate by 2-4 units every 3 days until fasting glucose reaches 80-130 mg/dL. 1, 2

Type 2 Diabetes: Standard Initiation

• Begin with 10 units once daily for most patients, which represents a safe, effective starting point regardless of body weight 1
• Alternatively, use 0.1-0.2 units/kg/day for weight-based dosing, with higher doses (0.2 units/kg) reserved for patients with more severe hyperglycemia 1, 2
• Continue metformin unless contraindicated, and possibly one additional non-insulin agent when initiating basal insulin 1

Severe Hyperglycemia Requires Higher Starting Doses

• For patients with HbA1c ≥9% or blood glucose ≥300-350 mg/dL, consider starting doses of 0.3-0.4 units/kg/day 1
• Patients with HbA1c 10-12% with symptomatic or catabolic features require immediate basal-bolus insulin rather than basal insulin alone 1

Type 1 Diabetes: Basal-Bolus Regimen Required

• Start with 0.5 units/kg/day total daily insulin for metabolically stable patients 1, 2
• Divide as 50% basal insulin (Lantus) once daily and 50% prandial insulin split among three meals 1
• Total daily insulin requirements typically range from 0.4-1.0 units/kg/day, with higher doses needed immediately following diabetic ketoacidosis 1, 2

Dose Titration Algorithm

• Increase by 2 units every 3 days if fasting glucose is 140-179 mg/dL 1
• Increase by 4 units every 3 days if fasting glucose is ≥180 mg/dL 1
• Target fasting plasma glucose: 80-130 mg/dL 1
• If hypoglycemia occurs without clear cause, reduce dose by 10-20% immediately 1

Timing of Administration

• Lantus can be administered at any time of day (morning, dinner, or bedtime) with equivalent efficacy 3, 4
• Morning administration results in significantly fewer nocturnal hypoglycemia episodes (59.5%) compared to dinner (71.9%) or bedtime (77.5%) dosing in type 1 diabetes 3
• For type 2 diabetes, morning versus bedtime administration shows no difference in nocturnal hypoglycemia or glycemic control 4

Critical Threshold: When to Stop Escalating Basal Insulin

• When basal insulin exceeds 0.5 units/kg/day, add prandial insulin or a GLP-1 receptor agonist rather than continuing to escalate basal insulin alone 1
• Clinical signals of overbasalization include: basal dose >0.5 units/kg/day, bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia, and high glucose variability 1

Special Populations Requiring Lower Doses

• Hospitalized patients on high-dose home insulin (≥0.6 units/kg/day): reduce total daily dose by 20% to prevent hypoglycemia 1
• High-risk patients (elderly >65 years, renal failure, poor oral intake): use 0.1-0.25 units/kg/day 1

Common Pitfalls to Avoid

• Never delay insulin initiation in patients not achieving glycemic goals with oral medications, as this prolongs hyperglycemia exposure 1
• Never continue escalating basal insulin beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia, as this causes overbasalization with increased hypoglycemia risk 1
• Never use sliding scale insulin as monotherapy—it is explicitly condemned by all major diabetes guidelines and should be replaced with scheduled basal insulin 1
• Do not mix Lantus with other insulins in the same syringe due to its low pH, which causes coprecipitation 1, 5

Monitoring Requirements

• Daily fasting blood glucose monitoring is essential during titration 1
• Reassess adequacy of insulin dose at every clinical visit, looking for signs of overbasalization 1
• Check HbA1c every 3 months during intensive titration 1