Diabetes Care, Vol 23, Issue 4 518-523, Copyright © 2000 by American Diabetes Association
Increased prandial insulin secretion after administration of a single preprandial oral dose of repaglinide in patients with type 2 diabetes
DR Owens, SD Luzio, I Ismail and T Bayer
Diabetes Research Unit, University of Wales College of Medicine, South Glamorgan, U.K. owensdr@cf.ac.uk
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.