Objective　A placebo-controlled, randomized, double-blind clinical trial was conducted to examine the efficacy and safety of concomitantly administering mitiglinide（Glufast tablets）for 16 weeks to type 2 diabetes mellitus patients without adequate glycemic control, despite receiving long-acting insulin only or a combination of long-acting insulin and an oral hypoglycemic agent with diet therapy.
Methods　One tablet of mitiglinide（10 mg）or placebo was administered three times daily before meals for 16 weeks to 178 diabetic patients receiving monotherapy with long-acting insulin or a combination of long-acting insulin and an oral hypoglycemic agent.
Results　The HbA1c decrease was significantly greater in the mitiglinide group than in the placebo group at the final evaluation. This decrease occurred regardless of whether or not an oral hypoglycemic agent was administered.
The postprandial plasma glucose level change was significantly greater in the mitiglinide group than in the placebo group with or without oral hypoglycemic agents, at the final evaluation, showing that mitiglinide lowers postprandial plasma glucose.
Thirteen patients had adverse drug reactions in the mitiglinide group. Hypoglycemia in mild and moderate severity occurred in 11 patients. However, severe hypoglycemia and treatment discontinuation case were not also observed.
Conclusions　Mitiglinide appears to be clinically useful as combination therapy with long-acting insulin in patients with type 2 diabetes mellitus