Increased prandial insulin secretion after administration of a single preprandial oral dose of repaglinide in patients with type 2 diabetes.

OBJECTIVE To examine the dose-related pharmacodynamics and pharmacokinetics of a single preprandial oral dose of repaglinide in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS A total of 16 Caucasian men with type 2 diabetes participated in two placebo-controlled double-blind randomized cross-over studies. Patients were randomized to receive a single oral dose of repaglinide (0.5, 1.0, and 2.0 mg in study 1 and 4.0 mg in study 2) or placebo (both studies) administered 15 min before the first of two sequential identical standard meals (breakfast and lunch) that were 4 h apart. During each of the study days, which were 1 week apart, blood samples were taken at frequent intervals over a period of approximately 8 h for measurement of plasma glucose, insulin, C-peptide, and repaglinide concentrations. RESULTS During the first meal period (0-240 min), administration of repaglinide reduced significantly the area under the curve (AUC) for glucose concentration and significantly increased the AUC for insulin levels, C-peptide levels, and the insulin secretion rate. These results, compared with those of administering placebo, were dose dependent and log linear. The effect of repaglinide administration on insulin secretion was most pronounced in the early prandial period. Within 30 min, it caused a relative increase in insulin secretion of up to 150%. During the second meal period (240-480 min), there was no difference between repaglinide and placebo administration in the AUC for glucose concentration, C-peptide concentration, and the estimated insulin secretion rate. CONCLUSIONS A single dose of repaglinide (0.5-4.0 mg) before breakfast improves insulin secretion and reduces prandial hyperglycemia dose-dependently Administration of repaglinide had no effect on insulin secretion with the second meal, which was consumed 4 h after breakfast.