Efficacy of glyburide/metformin tablets compared with initial monotherapy in type 2 diabetes

Many patients with type 2 diabetes fail to achieve or maintain the American Diabetes Association's recommended treatment goal of glycosylated hemoglobin levels. This multicenter, double-blind trial enrolled patients with type 2 diabetes who had inadequate glycemic control [glycosylated hemoglobin A_1C (A1C), >7% and <12%) with diet and exercise alone to compare the benefits of initial therapy with glyburide/metformin tablets vs. metformin or glyburide monotherapy. Patients (n = 486) were randomized to receive glyburide/metformin tablets (1.25/250 mg), metformin (500 mg), or glyburide (2.5 mg). Changes in A1C, fasting plasma glucose, fructosamine, serum lipids, body weight, and 2-h postprandial glucose after a standardized meal were assessed after 16 wk of treatment. Glyburide/metformin tablets caused a superior mean reduction in A1C from baseline (-2.27%) vs. metformin (-1.53%) and glyburide (-1.90%) monotherapy (P = 0.0003). Glyburide/metformin also significantly reduced fasting plasma glucose and 2-h postprandial glucose values compared with either monotherapy. The final mean doses of glyburide/metformin (3.7/735 mg) were lower than those of metformin (1796 mg) and glyburide (7.6 mg). First-line treatment with glyburide/metformin tablets provided superior glycemic control over component monotherapy, allowing more patients to achieve American Diabetes Association treatment goals with lower component doses in drug-naive patients with type 2 diabetes.