What is the initial bedtime dose of Lantus (insulin glargine) for a patient with hyperglycemia (blood sugar levels of 300-500 mg/dL)?

Initial Bedtime Lantus Dosing for Severe Hyperglycemia

For a patient with blood glucose levels of 300-500 mg/dL, start Lantus at 0.2 units/kg body weight once daily at bedtime, or use a flat dose of 10 units if weight-based calculation is not feasible. 1, 2

Dosing Algorithm Based on Clinical Severity

Standard Starting Dose

• The FDA-approved starting dose for insulin-naive type 2 diabetes patients is 0.2 units/kg body weight or up to 10 units once daily. 2
• The American Diabetes Association supports this range of 0.1-0.2 units/kg/day for insulin-naive patients, with 10 units being the typical flat dose. 3, 1

Higher Starting Dose for Severe Hyperglycemia

• For blood glucose levels of 300-500 mg/dL, which represents severe hyperglycemia, consider starting at the higher end of the dosing range (0.2 units/kg/day) or even 0.3-0.4 units/kg/day. 1
• The American Diabetes Association specifically recommends considering basal-bolus insulin (not just basal alone) when blood glucose is ≥300-350 mg/dL and/or HbA1c is 10-12%, especially if symptomatic or catabolic features are present. 3, 1

Critical Decision Point: Basal-Only vs. Basal-Bolus

• If the patient has symptomatic hyperglycemia (polyuria, polydipsia, weight loss) or catabolic features with glucose 300-500 mg/dL, start basal-bolus insulin immediately rather than basal insulin alone. 3, 1
• For basal-bolus regimens, use approximately 50% of total daily dose as basal insulin (Lantus) and 50% as prandial insulin divided among meals. 1

Rapid Titration Protocol

Dose Adjustment Schedule

• Increase the Lantus dose by 4 units every 3 days if fasting glucose remains ≥180 mg/dL. 1, 4
• Increase by 2 units every 3 days if fasting glucose is 140-179 mg/dL. 1
• Continue titration until fasting blood glucose reaches 80-130 mg/dL. 1

Patient Self-Titration

• Equip patients with self-titration algorithms to add 2 units every 3 days if fasting glucose remains above target, which achieves better glycemic control than clinic-managed titration alone. 5

Timing of Administration

Bedtime vs. Morning Dosing

• Lantus can be administered at bedtime or in the morning with equivalent efficacy, but bedtime dosing is associated with slightly higher rates of nocturnal hypoglycemia (77.5% vs. 59.5%). 6
• For patients with blood glucose 300-500 mg/dL, bedtime administration is reasonable as the risk of nocturnal hypoglycemia is lower when starting from severe hyperglycemia. 6, 7
• Administer at the same time every day once a timing is chosen. 2

Foundation Therapy Requirements

Continue Metformin

• Metformin must be continued when initiating insulin unless contraindicated, as it remains the foundation of type 2 diabetes therapy. 1
• Consider continuing one additional non-insulin agent alongside metformin and Lantus. 3, 1

Critical Thresholds and Warning Signs

Maximum Basal Insulin Dose

• When basal insulin 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
• Signs of "overbasalization" include bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia, and high glucose variability. 1

Hypoglycemia Management

• If hypoglycemia occurs, reduce the Lantus dose by 10-20% immediately. 1

Monitoring Requirements

Daily Glucose Monitoring

• Daily fasting blood glucose monitoring is essential during the titration phase. 1
• Increase the frequency of blood glucose monitoring during any insulin regimen changes. 2

Reassessment Timeline

• Reassess adequacy of insulin dose at every clinical visit, looking specifically for signs of overbasalization. 1
• If HbA1c remains above goal after 3-6 months of basal insulin optimization despite controlled fasting glucose, add prandial insulin. 1

Common Pitfalls to Avoid

Delayed Insulin Initiation

• Do not delay insulin therapy in patients with blood glucose 300-500 mg/dL, as this represents severe hyperglycemia requiring immediate intervention. 3, 1

Inadequate Dose Escalation

• Do not undertitrate the insulin dose; many patients with severe hyperglycemia require significantly more than 10 units to achieve adequate basal coverage. 4
• Waiting longer than 3 days between dose adjustments unnecessarily prolongs time to glycemic targets. 1

Ignoring Need for Prandial Insulin

• Blood glucose levels of 300-500 mg/dL likely reflect both inadequate basal coverage AND postprandial excursions, potentially requiring mealtime insulin from the start. 1

Administration Errors

• Never dilute or mix Lantus with any other insulin or solution due to its low pH. 2
• Do not administer intravenously or via an insulin pump. 2
• Rotate injection sites within the same region (abdomen, thigh, or deltoid) to reduce risk of lipodystrophy. 2