Background　Anagliptin is a novel dipeptidyl peptidase-4（DPP-4）inhibitor, and pharmacokinetic and pharmacodynamic properties of anagliptin have been investigated in healthy volunteers and in type 2 diabetes patients. In this study, we investigated the drug interaction between anagliptin and miglitol, an α-glucosidase inhibitor, in Japanese subjects with type 2 diabetes.
Methods　A total 18 subjects enrolled in this study received 100 mg of anagliptin twice a day and/or with 50 mg of miglitol 3 times a day for 3 days in an open-label 3-period crossover design. The pharmacokinetic and pharmacodynamic parameters were determined in each period.
Results　The maximum concentration（C_maxsub>）and area under the curve（AUC）_0-24h of anagliptin were decreased by concomitant administration with miglitol. The ratio of inhibition of DPP-4 activity, however, did not change markedly during 12 h on concomitant administration of miglitol. Anagliptin or miglitol alone showed a significant decrease of both fasting and postprandial glucose levels. Concomitant administration of two drugs decreased the plasma glucose levels much more significantly compared with anagliptin or miglitol alone. In addition, the postprandial levels of active glucagon-like peptide-1（GLP-1）were significantly higher in concomitant use of two drugs than in a single use of anagliptin or miglitol. We did not observe any clinically important adverse events.
Conclusions　Concomitant administration of anagliptin and miglitol improved the blood glucose control and increased the postprandial level of plasma active GLP-1 more effectively than either of the drugs alone. These results suggest that combination therapy with anagliptin and miglitol would be effective in the treatment of type 2 diabetes.