Should I start Lantus (insulin glargine) in a patient with severe hyperglycemia and HbA1c >14.0% on Metformin (Metformin) 500mg?

From the Guidelines

Initiating Lantus (insulin glargine) is appropriate for a patient with severe hyperglycemia and HbA1c >14.0% who is currently only on Metformin 500mg. A typical starting dose would be 10 units of Lantus once daily, usually administered at bedtime, as suggested by the American Diabetes Association standards of medical care in diabetes 1. The dose can be titrated upward by 2-4 units every 3-4 days until the fasting blood glucose target (typically 80-130 mg/dL) is achieved. Continue the Metformin 500mg while adding the insulin therapy, as it is beneficial to continue metformin with insulin therapy to reduce hepatic glucose production and improve peripheral insulin sensitivity 1. The patient should monitor blood glucose levels at least twice daily, particularly fasting levels in the morning. This combination approach is necessary because the patient's current regimen is clearly insufficient to control their diabetes, with an HbA1c >14.0% indicating average blood glucose levels above 350 mg/dL, putting the patient at risk for complications including diabetic ketoacidosis. Insulin glargine provides a steady basal insulin level over 24 hours, addressing the continuous hyperglycemia, while Metformin continues to work on reducing hepatic glucose production and improving peripheral insulin sensitivity. Once glucose levels stabilize, the treatment plan can be reassessed, potentially including optimization of the Metformin dose (up to 2000mg daily in divided doses) and consideration of additional oral agents, as suggested by the management of hyperglycemia in type 2 diabetes position statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) 1. Key considerations include:

• Starting with a basal insulin, such as Lantus, in patients with severe hyperglycemia and HbA1c >14.0%
• Titration of the insulin dose based on fasting blood glucose levels
• Continuation of metformin with insulin therapy to improve glycemic control
• Monitoring of blood glucose levels to adjust the treatment plan as needed
• Consideration of additional oral agents or optimization of the metformin dose once glucose levels stabilize.

From the FDA Drug Label

1. 3 Initiation of Insulin Glargine Therapy Recommended Starting Dosage in Patients with Type 2 Diabetes The recommended starting dosage of Insulin Glargine in patients with type 2 diabetes who are not currently treated with insulin is 0.2 units/kg or up to 10 units once daily.

The patient has severe hyperglycemia and HbA1c >14.0% on Metformin 500mg. Starting Lantus (insulin glargine) is recommended. The recommended starting dosage is 0.2 units/kg or up to 10 units once daily. Dosage adjustments may be needed based on the patient's metabolic needs, blood glucose monitoring results, and glycemic control goal. Close medical supervision with increased frequency of blood glucose monitoring is advised. 2

From the Research

Patient Profile

• HbA1c level: >14.0%
• Fasting glucose: 400
• Current medication: Metformin 500mg
• Consideration: Addition of Lantus (insulin glargine)

Studies on Insulin Glargine

• A study published in 2006 3 compared the addition of insulin glargine to conventional therapy with oral agents in patients with Type 2 diabetes. The results showed that adding insulin glargine was more likely to achieve a lower HbA1c level than conventional therapy.
• Another study published in 2017 4 discussed the use of insulin in patients with HbA1c >9% and suggested that insulin may not always be the preferred treatment option, especially with the availability of other therapeutic approaches such as metformin, incretin-based treatments, and SGLT2 inhibitors.
• A study published in 2006 5 compared the addition of glargine insulin or rosiglitazone to metformin and sulfonylurea in poorly controlled Type 2 diabetic patients. The results showed that both glargine insulin and rosiglitazone reduced HbA1c levels, primarily by suppressing basal endogenous glucose production.
• The LANMET study 6 compared the combination of insulin glargine and metformin with NPH insulin and metformin in Type 2 diabetic patients. The results showed that both combinations achieved good glycemic control, but insulin glargine reduced symptomatic hypoglycemia during the first 12 weeks and dinner-time hyperglycemia.
• A study published in 2019 7 investigated the effectiveness and safety of adding basal insulin glargine to patients with Type 2 diabetes mellitus exhibiting inadequate response to metformin and DPP-4 inhibitors with or without sulfonylurea. The results showed that the combination add-on therapy was safe and efficient in reducing HbA1c levels.

Considerations for Lantus (Insulin Glargine) Use

• The patient's high HbA1c level (>14.0%) and fasting glucose (400) indicate poor glycemic control, which may require the addition of insulin therapy.
• The patient is already on metformin 500mg, which is a common first-line treatment for Type 2 diabetes.
• The studies suggest that adding insulin glargine to metformin can be an effective way to achieve better glycemic control, especially in patients with high HbA1c levels.
• However, the decision to start Lantus (insulin glargine) should be based on individual patient factors, such as the presence of symptoms, weight, and other comorbidities.