What is the best course of action for a patient with poorly controlled type 2 diabetes mellitus (T2DM) on Lantus (insulin glargine) 60 units nightly and Glipizide (glyburide) 10mg with a hemoglobin A1C (HbA1C) level over 15?

Immediate Insulin Intensification Required

Add basal insulin immediately to your current regimen of Lantus 60 units and glipizide 10mg—this patient's A1C >15% represents severe hyperglycemia requiring urgent treatment intensification with insulin as the most effective glucose-lowering agent available. 1, 2

Why Insulin Intensification is Critical Now

• With A1C >15%, this patient has severe glucose toxicity that is actively impairing both insulin secretion and insulin sensitivity, creating a vicious cycle that only insulin can reliably break 2, 3
• The American Diabetes Association explicitly recommends initiating or intensifying insulin therapy when A1C >10%, and this patient far exceeds that threshold 1, 2
• At this level of hyperglycemia, glucose toxicity itself is causing reversible beta-cell dysfunction—prompt insulin therapy can restore beta-cell function once glucotoxicity resolves 3

Specific Treatment Plan

Increase Basal Insulin Dose

• Increase Lantus from 60 units to 80 units nightly (approximately 30% increase), as the current dose is clearly insufficient 4, 5
• Titrate upward by 4-6 units every 3 days based on fasting blood glucose until fasting glucose reaches 4.4-7.0 mmol/L (80-126 mg/dL) 5, 2

Continue Metformin (if not already prescribed)

• If the patient is not on metformin, add metformin 1000mg twice daily immediately (start 500mg twice daily for one week to minimize GI side effects, then increase) 1, 2
• Metformin must be continued as it works synergistically with insulin, reduces insulin requirements by 29%, and prevents weight gain associated with insulin intensification 6, 2

Modify Glipizide Dosing

• Continue glipizide 10mg initially as there is evidence sulfonylureas can effectively treat severe hyperglycemia in type 2 diabetes 2, 1
• Plan to reduce glipizide to 5mg daily once Lantus dose exceeds 80-90 units to minimize hypoglycemia risk from the combination 2, 7

Consider Adding Mealtime Insulin

• If fasting glucose normalizes but A1C remains >9% after 4-6 weeks, add rapid-acting insulin 4-6 units before the largest meal to address postprandial hyperglycemia 1
• This represents progression to basal-bolus therapy, which may be necessary given the severity of hyperglycemia 1

Alternative: Short-Term Intensive Insulin Therapy

For newly diagnosed patients or those with diabetes duration <2 years, consider 2-3 weeks of intensive insulin therapy (multiple daily injections or insulin pump) to rapidly reverse glucose toxicity, which can induce prolonged remission in 42-66% of patients. 3, 1

• This approach involves temporary use of basal-bolus insulin (basal insulin plus mealtime rapid-acting insulin before each meal) for 2-3 weeks to achieve strict normoglycemia 3
• After glucose toxicity resolves, many patients can transition back to oral agents or reduced insulin doses 3, 1
• Predictors of success include shorter diabetes duration (<2 years), higher BMI, and better baseline beta-cell function 3

Critical Safety Measures

Hypoglycemia Education (Urgent Priority)

• The combination of insulin plus sulfonylurea significantly increases hypoglycemia risk—educate immediately on recognition (tremor, sweating, confusion, palpitations) and treatment using the 15-15 rule: consume 15-20g rapid-acting glucose and recheck in 15 minutes 8, 2
• Provide glucose tablets or gel and ensure the patient understands when to seek emergency care 8

Monitoring Protocol

• Check fasting blood glucose daily and adjust Lantus dose every 3 days based on the average of the previous 3 days' readings 5, 2
• Recheck A1C in 3 months (not sooner, as A1C reflects 2-3 month average) 1, 2
• Schedule follow-up in 2-4 weeks to assess insulin titration, hypoglycemia episodes, and medication adherence 2

Vitamin B12 Monitoring

• If continuing or adding metformin, check vitamin B12 levels annually as metformin use is associated with B12 deficiency and worsening neuropathy 1, 2

Expected Outcomes

• Expect A1C reduction of 2-3% or more with aggressive insulin intensification combined with metformin 2, 6
• With A1C >15%, achieving A1C <10% within 3 months is a realistic initial goal, with further reduction to <8% by 6 months 1, 9
• As glucose toxicity resolves over 2-3 months, you may be able to simplify the regimen or reduce insulin doses 1, 3

Common Pitfalls to Avoid

Do Not Delay Insulin Intensification

• Therapeutic inertia at this A1C level worsens outcomes and prolongs glucose toxicity—every month of delay increases complication risk 2, 9
• The typical practice of waiting 3 months between medication adjustments is inappropriate when A1C is this severely elevated 9

Do Not Discontinue Metformin When Intensifying Insulin

• Metformin should be continued for its insulin-sensitizing effects, reduction in insulin requirements, prevention of weight gain, and cardiovascular benefits 6, 2

Do Not Use Timid Insulin Dose Increases

• With A1C >15%, small 2-unit adjustments are insufficient—use 4-6 unit increases every 3 days until fasting glucose normalizes 5, 2

Do Not Add a Third Oral Agent Instead of Insulin

• While SGLT-2 inhibitors show benefit when added as a third agent 10, insulin is far more effective at this level of severe hyperglycemia and should be prioritized 1, 2

Cost Considerations

• If cost is a barrier, NPH insulin is the most cost-effective basal insulin option and should be strongly considered, though it requires twice-daily dosing and has higher hypoglycemia risk than Lantus 2
• Generic metformin and glipizide are inexpensive and should be continued 1, 7