The case reports a woman in her 70s, with type 2 diabetes and chronic kidney disease in G4 stage. The patient had elevated HbA1c, and she was switched from linagliptin, a dipeptidyl peptidase 4 inhibitor, to dulaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA). Thereafter, the HbA1c level decreased; however, since the dulaglutide supply became a problem, the patient was switched to tirzepatide, a glucose-dependent insulinotropic polypeptide (GIP)/GLP-1RA. To date, no clinical studies have evaluated the efficacy and safety of switching from GLP-1RA to GIP/GLP-1RA, but we report this case because efficacy was observed in this patient. The therapeutic effects after switching to tirzepatide included decrease in HbA1c, increase in eGFR, and decrease in BUN, when compared to when dulaglutide was used. A change from dulaglutide to tirzepatide, could inhibit renal impairment progression and improve renal function.