Basal Insulin Should Be Added to Current Therapy
For a patient with type 2 diabetes on metformin and sulfonylurea with HbA1c of 11.2%, basal insulin should be added immediately to the current regimen, with consideration to discontinue the sulfonylurea once insulin is titrated to reduce hypoglycemia risk. 1
Rationale for Insulin Initiation
When HbA1c exceeds 11% (97 mmol/mol), basal insulin introduction is well-established and strongly recommended, particularly given this represents severe hyperglycemia 1
The 2025 ADA Standards explicitly state it is common practice to initiate insulin therapy for patients presenting with HbA1c >10% (>86 mmol/mol), even without catabolic symptoms 1
At this level of hyperglycemia, insulin is likely to be more effective than adding another oral agent, as most oral medications rarely exceed a 1% reduction in HbA1c 1
Specific Insulin Regimen
Start with long-acting basal insulin (insulin glargine or insulin detemir) at 10 units once daily at bedtime, or calculate 0.1-0.2 units/kg body weight as the starting dose 2
Continue metformin, as it provides complementary glucose-lowering through different mechanisms and reduces insulin requirements 3
Strongly consider discontinuing the sulfonylurea once insulin is initiated, as combining sulfonylurea with insulin dramatically increases hypoglycemia risk without substantial additional benefit 2, 4
Titration and Monitoring
Increase basal insulin by 2-4 units every 3-7 days based on fasting glucose readings, targeting fasting glucose <130 mg/dL (7.2 mmol/L) 2
Monitor fasting blood glucose daily during the titration phase 2
Recheck HbA1c after 3 months to assess overall glycemic control 1, 2
Alternative Consideration: GLP-1 Receptor Agonists
While insulin is the traditional recommendation, recent evidence suggests GLP-1 receptor agonists can be equally or more effective at this HbA1c level 5:
Studies show GLP-1 RAs can reduce HbA1c by 2.5-3.1% from baseline levels of 10-11%, comparable to or exceeding insulin glargine 5
GLP-1 RAs offer the advantage of weight loss rather than weight gain, and lower hypoglycemia risk 5
However, insulin remains the most established and guideline-recommended approach for HbA1c >11%, with more extensive clinical experience in this severe hyperglycemia range 1
Critical Pitfall to Avoid
Do not continue the sulfonylurea-insulin combination long-term. The combination of sulfonylurea with insulin increases hypoglycemia events substantially compared to insulin alone, with incidence rates of 36.8% with insulin alone versus higher rates when combined with sulfonylureas 4, 3. Once insulin is adequately titrated, the sulfonylurea should be discontinued 2.
Why Not Just Add Another Oral Agent?
Initial combination therapy or more aggressive approaches are recommended when HbA1c is >1.5% above target 1
At 11.2%, this patient is approximately 4% above the typical 7% target, far exceeding the threshold for insulin consideration 1
The progressive nature of type 2 diabetes means dual oral therapy has already failed, and adding a third oral agent is unlikely to achieve adequate control at this HbA1c level 6