[The Beneficial Effects of Switching from Dipeptidyl Peptidase-4 Inhibitors to Dulaglutide on Plasma Glucose and Hemoglobin A1c Levels: A Case Report of Four Patients with Type 2 Diabetes].

　Incretin-based therapy consists of dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. Whether switching from DPP-4 inhibitors to one of the GLP-1 receptor agonists, dulaglutide, has greater beneficial effects remains unknown. Therefore, this study aimed to investigate the effectiveness of switching from DPP-4 inhibitors to dulaglutide in four patients with type 2 diabetes. All four patients with hyperglycemia who switched from DPP-4 inhibitors to dulaglutide demonstrated noticeable decreased plasma glucose levels on the next day after switching. Two of the patients observed maintained a decreased plasma glucose level over 14 day after switching. Moreover, all patients demonstrated decreased glycosylated hemoglobin A1c levels during the observation period (1-6 months) after switching and lost weight from 6 to 27 day. Minor and manageable hypoglycemia, nausea, and diarrhea were observed as side effects in one case. The current findings suggest that dulaglutide is a suitable treatment alternative in patients with type 2 diabetes who are not currently achieving adequate glycemic control with DPP-4 inhibitors.