Safety and efficacy of repaglinide in combination with metformin and bedtime NPH insulin as an insulin treatment regimen in type 2 diabetes

Objective: To evaluate the efficacy and safety of the association of repaglinide, metformin and bedtime NPH insulin compared to two classic regimens: metformin plus NPH and two doses of NPH in patients with poorly controlled type 2 diabetes despite two or more oral antidiabetic drugs (OADs). Patients and methods: Random, parallel and open study of 24 weeks with 37 patients randomized into three therapeutic groups: group A (n = 12) (repaglinide/metformin/NPH), group B (n = 12) (metformin/NPH) and group C (n = 13) (NPH/NPH). The insulin was adjusted in the visits to obtain a basal blood glucose <110 mg/dl. The endpoint criteria included HbA1c, blood glucose profile, hypoglycemias and body weight. Results: At the end of the study, group A presented HbA1c (mean ± standard deviation) 7.2 ± 0.7%, which was significantly less than B (8.8 ± 0.1%) and C (8.4 ± 1.2%). In terms of absolute reduction, there were only differences (p = 0.01) between group A (-2.4 ± 1.1%) and B (-0.7 ± 1.2%). Group A presented lower postprandial blood glucose values (p < 0.01). Nor were there any significant differences in weight gain and incidence of hypoglycemia. Conclusions: The combination of repaglinide, metformin and bedtime NPH is safe and effective and it provides better postprandial blood glucose control. The association of metformin and a dose of NPH does not obtain suitable control in patients with a long evolution who have already received two or more OADs.