Beneficial effects of a glyburide/metformin combination preparation in Type 2 diabetes mellitus

Background: Type 2 diabetes mellitus is characterized by both insulin deficiency and insulin resistance. Effective treatment often requires therapy directed at both abnormalities. Patients on monotherapy might benefit from a combination agent such as glyburide/metformin, which increases insulin secretion and reduces insulin resistance. Methods: All patients taking a glyburide/metformin preparation at the Carl T. Hayden VAMC were identified from pharmacy records. Patients with documented hemoglobin A(1c) values within 31 weeks prior and between 3 and 33 weeks after initiation of therapy (92 subjects) were examined. Results: Glyburide/metformin combination therapy reduced hemoglobin A(1c) levels from 0.087 to 0.083 (P < 0.06). Significant reductions were seen in those patients with initial levels higher than 0.08 (0.094 to 0.087; P < 0.01). No significant reductions were seen in those patients with initial levels lower than 0.08. Conclusions: In patients on monotherapy or on dual oral therapy with inadequate control, changing to a glyburide/metformin combination preparation may improve glucose control.