How to manage hyperglycemia in a patient taking Lantus (insulin glargine) and Metformin?

Management of Hyperglycemia with Blood Sugar of 360 mg/dL

For a patient with a blood sugar of 360 mg/dL who is currently on Lantus (insulin glargine) and metformin, immediate intensification of insulin therapy is required by adding rapid-acting insulin before meals while adjusting the basal insulin dose.

Immediate Management

• For severe hyperglycemia (>300 mg/dL), rapid-acting insulin should be administered immediately to lower blood glucose levels 1
• A starting dose of 6 units of rapid-acting insulin analog (insulin aspart, lispro, or glulisine) should be given subcutaneously to address the current hyperglycemia 1
• Check blood glucose 3 hours after administration to assess response 1
• Assess for ketosis - if moderate to severe ketosis is present (ketonuria 2+ or ketonemia ≥1.5 mmol/L), consider transfer to higher level of care for IV insulin therapy 1

Short-Term Treatment Plan

• Increase the current Lantus (insulin glargine) dose systematically to 0.1-0.2 units/kg/day if not already at this level 2
• Add prandial (mealtime) insulin therapy with rapid-acting insulin analogs before meals 1
• Initial prandial insulin dosing should be approximately 4 units before each meal, or calculated as 50% of total daily insulin divided among three meals 2
• Continue metformin at the current dose as it complements insulin therapy by reducing insulin resistance 1
• Titrate basal insulin (Lantus) by adding 2-4 units every 3 days until fasting blood glucose approaches target range of 100-120 mg/dL 2

Insulin Adjustment Algorithm

• Adjust basal insulin (Lantus) by adding 1-2 units (or 5-10% for higher doses) once or twice weekly if fasting glucose remains above target 1
• Adjust prandial insulin based on pre-meal and 2-hour post-meal glucose readings 1
• Target pre-meal glucose of 80-130 mg/dL and post-meal glucose <180 mg/dL 1
• Monitor for hypoglycemia, especially during the initial titration phase 2, 3

Patient Education

• Provide comprehensive education on proper insulin injection technique, timing, and storage 1
• Teach blood glucose monitoring schedule: before meals, at bedtime, and occasionally 2 hours after meals 1
• Educate about hypoglycemia recognition, prevention, and treatment 1, 2
• Review "sick day" management rules to prevent severe hyperglycemia during illness 1

Important Considerations

• If the patient has catabolic features (weight loss, ketosis) or very high HbA1c (≥10%), a more aggressive insulin regimen is warranted 1
• Once glycemic control is achieved, it may be possible to reduce insulin doses, but this should be done gradually 1
• Drug interactions: monitor for increased hypoglycemia risk when insulin is used with ACE inhibitors, fibrates, salicylates, or other medications that enhance insulin sensitivity 3
• Avoid alcohol consumption as it potentiates the effect of metformin on lactate metabolism and increases hypoglycemia risk 4

Common Pitfalls to Avoid

• Failing to intensify insulin therapy promptly when blood glucose is severely elevated 1, 2
• Inadequate patient education about insulin administration and glucose monitoring 1, 2
• Insufficient insulin dose adjustments - systematic titration is necessary 1, 2
• Neglecting to check for ketosis in the setting of severe hyperglycemia 1
• Continuing to increase insulin without addressing potential insulin resistance factors 5

By following this approach, the patient's severe hyperglycemia can be addressed immediately while establishing a sustainable insulin regimen for long-term glycemic control.