What is the appropriate starting dose and administration instructions for insulin glargine (Lantus) as basal therapy in an adult patient weighing 86.6 kg?

Insulin Glargine (Lantus) Prescription for Basal Therapy

For a patient weighing 86.6 kg starting basal insulin therapy, prescribe Lantus 10 units subcutaneously once daily at bedtime, with systematic titration every 3 days based on fasting glucose values until reaching target of 80-130 mg/dL. 1, 2

Prescription Details

Medication: Lantus (insulin glargine) 100 units/mL
Dose: 10 units subcutaneously once daily
Timing: Administer at bedtime (or any consistent time each day)
Supply: Dispense one 10 mL vial or SoloStar prefilled pens

1, 2

Rationale for Starting Dose

• The American Diabetes Association recommends 10 units once daily OR 0.1-0.2 units/kg/day as the standard starting dose for insulin-naive patients with type 2 diabetes 1
• For this 86.6 kg patient, the weight-based calculation yields 8.7-17.3 units/day, making 10 units an appropriate conservative starting point 1
• The FDA-approved prescribing information for Lantus specifies 0.2 units/kg or up to 10 units once daily as the recommended starting dosage in type 2 diabetes patients not currently treated with insulin 2
• Starting with 10 units rather than the higher weight-based dose (17 units) reduces initial hypoglycemia risk while allowing for systematic titration 1

Patient Instructions for Self-Titration

Target fasting glucose: 80-130 mg/dL 1

Titration schedule (adjust every 3 days):

• If fasting glucose 140-179 mg/dL: increase dose by 2 units 1
• If fasting glucose ≥180 mg/dL: increase dose by 4 units 1
• If fasting glucose <80 mg/dL on more than 2 occasions per week: decrease dose by 2 units 1
• If hypoglycemia occurs without clear cause: reduce dose by 10-20% immediately 1

Administration Instructions

• Inject subcutaneously into the abdomen, thigh, or deltoid region 2
• Rotate injection sites within the same region to reduce risk of lipodystrophy 2
• Administer at the same time every day (preferably bedtime, but any consistent time is acceptable) 1, 2
• Do NOT mix or dilute with any other insulin or solution 2
• Visually inspect before each injection; use only if clear and colorless with no particles 2

Daily Monitoring Requirements

• Check fasting blood glucose every morning during titration phase 1
• Record all fasting glucose values to guide dose adjustments every 3 days 1
• Continue current metformin therapy unless contraindicated 1

Critical Threshold Warning

• When Lantus dose exceeds 0.5 units/kg/day (approximately 43 units for this patient), this signals the need for mealtime insulin coverage rather than further basal insulin increases 1
• Signs of "overbasalization" requiring prandial insulin addition include: basal dose >0.5 units/kg/day, bedtime-to-morning glucose drop ≥50 mg/dL, hypoglycemia episodes, or high glucose variability 1

Hypoglycemia Management

• Treat immediately if glucose <70 mg/dL with 15 grams of fast-acting carbohydrate 1
• Recheck glucose in 15 minutes and repeat treatment if needed 1
• Always carry a source of fast-acting carbohydrates 1

When to Contact Provider

• Fasting glucose remains >180 mg/dL after 2-3 weeks of titration 1
• Lantus dose exceeds 0.5 units/kg/day (43 units) without achieving fasting glucose targets 1
• Recurrent hypoglycemia despite dose reductions 1
• Any severe hypoglycemia requiring assistance 1

Follow-Up Schedule

• Reassess every 3 days during active titration to adjust dose 1
• Check HbA1c in 3 months to assess overall glycemic control 1
• Consider adding prandial insulin if HbA1c remains above target after 3-6 months despite achieving fasting glucose goals 1