What is the appropriate starting dose of Lantus (insulin glargine) for a 63-year-old female patient weighing 236 pounds?

Starting Lantus Dose for a 63-Year-Old Female Weighing 236 lbs

For this 236 lb (107 kg) patient with type 2 diabetes, start with 10 units of Lantus subcutaneously once daily at the same time each day, or alternatively use weight-based dosing of 0.2 units/kg (approximately 21 units once daily). 1, 2

Initial Dosing Strategy

The FDA-approved starting dose for insulin-naive type 2 diabetes patients is 0.2 units/kg or up to 10 units once daily 2. For this patient:

• Fixed-dose approach: 10 units once daily 1, 2
• Weight-based approach: 0.2 units/kg × 107 kg = 21 units once daily 2

The American Diabetes Association guidelines support a starting range of 0.1-0.2 units/kg/day for insulin-naive type 2 diabetes patients 1. The conservative 10-unit starting dose minimizes hypoglycemia risk, while the weight-based approach (21 units) may achieve glycemic targets more rapidly in this heavier patient 1.

Dose Titration Protocol

Increase the dose by 2-4 units every 3 days based on fasting blood glucose levels until reaching target fasting glucose of 80-130 mg/dL 1, 3:

• If fasting glucose ≥180 mg/dL: increase by 4 units every 3 days 1, 3
• If fasting glucose 140-179 mg/dL: increase by 2 units every 3 days 1, 3
• If fasting glucose <80 mg/dL on more than 2 occasions per week: decrease by 2 units 1

Alternatively, increase by 10-15% of the current dose once or twice weekly 1, 3. Patient-driven titration (where the patient adjusts their own dose following this algorithm) achieves better HbA1c reduction than clinic-driven titration (-1.8% vs -1.5%) with acceptable hypoglycemia rates 4, 5.

Administration Guidelines

• Administer once daily at the same time each day (morning, evening, or bedtime—consistency matters more than timing) 2, 6
• Inject subcutaneously into abdomen, thigh, or deltoid 2
• Rotate injection sites within the same region to prevent lipodystrophy 2
• Do not mix or dilute with any other insulin or solution 2, 6
• Continue metformin unless contraindicated, as it remains the foundation of type 2 diabetes therapy 1

Critical Decision Points and Pitfalls

When to Add Prandial Insulin

If basal insulin exceeds 0.5 units/kg/day (approximately 54 units for this patient) and HbA1c remains above target despite controlled fasting glucose, add prandial insulin rather than continuing to escalate basal insulin 1, 3. For this 107 kg patient, once the Lantus dose approaches 54 units/day without achieving HbA1c goals, adding rapid-acting insulin before the largest meal (starting with 4 units or 10% of basal dose) is more appropriate than further basal insulin increases 1.

Signs of Overbasalization to Avoid

Watch for these warning signs that indicate excessive basal insulin 1:

• Basal dose >0.5 units/kg/day (>54 units for this patient)
• High bedtime-to-morning glucose differential (≥50 mg/dL)
• Hypoglycemia episodes
• High glucose variability despite adequate basal dosing

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, 3.

Monitoring Requirements

• Daily fasting blood glucose monitoring during titration phase 1, 3
• Reassess every 3 days during active titration 1
• Reassess every 3-6 months once stable 1
• If hypoglycemia occurs, determine the cause and reduce dose by 10-20% 1, 3

Special Considerations for This Patient

At 236 lbs (107 kg), this patient likely has significant insulin resistance 6. If she has severe hyperglycemia at presentation (HbA1c ≥9%, blood glucose ≥300-350 mg/dL, or symptomatic/catabolic features), consider higher starting doses of 0.3-0.4 units/kg/day (32-43 units) 1. In obese, insulin-resistant patients requiring very high insulin volumes, twice-daily Lantus administration may be more effective than once-daily dosing 6.

Expected Outcomes

With appropriate titration, expect HbA1c reduction of 1.4-1.7% over 24 weeks when adding Lantus to oral agents 4. The incidence of severe hypoglycemia should be <1% with proper titration 4, 7. More than 50% of type 2 diabetes patients can achieve HbA1c <7% with once-daily Lantus combined with oral agents 8.