Oral Hypoglycemic Agents Added to Insulin Monotherapy for Type 2 Diabetes.

CLINICAL QUESTION: Among patients with type 2 diabetes mellitus who do not achieve optimal glycemic control with insulin monotherapy, is the addition of oral hypoglycemic agents associated with benefits (measured by lowering of hemoglobin A1c) or adverse effects? BOTTOM LINE: Adding a sulfonylurea to insulin was associated with more hypoglycemic events compared with insulin alone, but this association was not observed for metformin. Adding a sulfonylurea or metformin to insulin was associated with a decrease in hemoglobin A1c of approximately 1.0%.