Glibenclamide in patients with poorly controlled type 2 diabetes: a 12-week, prospective, single-center, open-label, dose-escalation study.

Background: The purpose of this study was to investigate the effect of glibenclamide dose escalation on blood glucose and insulin in patients with poorly controlled type 2 diabetes.

Methods: Twenty-two subjects with type 2 diabetes were administered increasing doses (0, 2.5, 5, 10, and 20 mg/day) of glibenclamide at 2-week intervals. Glibenclamide, glucose, and insulin determinations were performed.

Results: The decrease in mean blood glucose from zero dose was 20%, 22%, 26%, and 28% for doses of 2.5, 5, 10, and 20 mg/day, respectively, which was significant from zero dose to 2.5 mg/day (P≤0.001). There were no significant decreases in glucose concentration beyond 2.5 mg/day. The percentage increase in mean insulin from zero dose was 51%, 58%, 44%, and 33% for 2.5, 5, 10, and 20 mg/day respectively. Mean blood insulin increased significantly from zero dose to 2.5 mg/day (P≤0.001). There were no significant increases in mean insulin concentration beyond 2.5 mg/day.

Conclusion: The results of this study suggest that increasing doses of glibenclamide do not produce a proportional increase in insulin secretion or a proportional decrease in blood glucose concentration.