How to manage poor glycemic control on 46 units of Humalog (insulin lispro) 75/25 and 16 units of Lantus (insulin glargine)?

Management of Poor Glycemic Control on Humalog 75/25 and Lantus

For a patient with poor glycemic control on 46 units of Humalog 75/25 and 16 units of Lantus, the most effective approach is to intensify therapy by either adding a GLP-1 receptor agonist or transitioning to a basal-bolus insulin regimen.

Current Regimen Assessment

• The patient is currently on a combination of premixed insulin (Humalog 75/25) and basal insulin (Lantus), which is an unusual regimen that may be contributing to poor control 1
• When a patient is on basal insulin exceeding 0.5 units/kg/day (as likely in this case with 16 units Lantus plus 46 units of premixed insulin) and still has poor glycemic control, intensification of therapy is indicated 1
• The current regimen combines two different insulin delivery approaches (basal-only and premixed), which can lead to unpredictable glucose patterns and difficulty with dose adjustments 1

Recommended Treatment Options

Option 1: Transition to Basal-Bolus Insulin Regimen

• Convert to a structured basal-bolus insulin regimen with basal insulin once daily and rapid-acting insulin before meals 1
• Calculate total daily insulin dose (current 62 units total) and redistribute as:
  • 50% as basal insulin (approximately 30-31 units of Lantus) 1
  • 50% as prandial insulin divided across meals based on carbohydrate content (approximately 10-11 units per meal of rapid-acting insulin) 1
• Titrate basal insulin to target fasting plasma glucose <5.6 mmol/L (100 mg/dL) without hypoglycemia 1
• Adjust prandial insulin doses based on pre-meal and post-meal glucose patterns 1

Option 2: Add GLP-1 Receptor Agonist

• Add a once-weekly GLP-1 receptor agonist while simplifying the insulin regimen 1, 2
• Consider transitioning to basal insulin only (approximately 40-50% of current total daily dose) plus GLP-1 receptor agonist 2
• This approach has demonstrated comparable HbA1c reduction to basal-bolus regimens with advantages of weight loss and lower hypoglycemia risk 2
• Studies show that adding a GLP-1 receptor agonist to basal insulin can be as effective as adding prandial insulin for patients with inadequate control 2

Monitoring and Titration

• After regimen change, reassess and modify regularly (every 3-6 months) to avoid therapeutic inertia 1
• Set clear fasting plasma glucose goals and establish an evidence-based titration algorithm 1
• For basal insulin: increase by 2 units every 3 days until reaching target fasting glucose without hypoglycemia 1, 3
• For prandial insulin: adjust based on pre-meal and post-meal glucose patterns 1
• If hypoglycemia occurs, determine the cause and reduce the corresponding dose by 10-20% 1

Special Considerations

• Discontinue sulfonylureas when using multiple daily insulin injections to avoid unnecessary hypoglycemia risk 1
• Metformin should be continued as it improves insulin sensitivity 1
• Consider factors that may contribute to poor control such as:
  • Duration of diabetes (longer duration associated with poorer control) 4
  • Medication adherence and timing 4
  • Insulin injection technique and rotation of sites 5
  • Carbohydrate counting accuracy 1

Potential Pitfalls and How to Avoid Them

• Overbasalization: Watch for elevated bedtime-to-morning glucose differentials or nocturnal hypoglycemia 1
• Insulin stacking: Ensure appropriate spacing between multiple daily injections 1
• Hypoglycemia risk: Monitor closely during transition, especially with basal-bolus regimens 5, 6
• Patient burden: Consider patient preference and ability to manage multiple injections versus simpler regimens 2
• Localized cutaneous amyloidosis: Ensure proper rotation of injection sites to prevent this complication 5

By implementing these evidence-based approaches, glycemic control can be improved while minimizing risks of hypoglycemia and other adverse events.