The prescription of sodium-glucose cotransporter-2 (SGLT2) inhibitors have been increasing due to their additional benefits, including weight loss, cardioprotection and renoprotection. Accordingly, there are concerns about the potential rise in severe adverse drug reactions (ADRs), such as urinary tract infections, diabetic ketoacidosis, volume depletion, and hypoglycemia. The Society has announced recommendations on the proper use of SGLT2 inhibitors. We aimed to elucidate the recent occurrence of severe ADRs which need discontinuation of SGLT2 inhibitors or hospitalization. In this retrospective cohort study, we identified 391 diabetic patients who were prescribed SGLT2 inhibitors upon admission to our hospital between April 2017 and March 2023. Of these, 68 patients who discontinued SGLT2 inhibitors for reasons other than ADRs were excluded. Patients were classified into the 2017 group and the 2020 group based on the treatment period of SGLT2 inhibitors, and the occurrence of ADRs and patient backgrounds were compared between the two groups. A total of 323 eligible patients were identified. Discontinuations of SGLT2 inhibitors decreased in the 2020 group (p < 0.05). However, discontinuations due to frailty increased (p < 0.05). Hospitalization due to ADRs, specifically those due to urinary tract infections, diabetic ketoacidosis, or volume depletion, did not specifically decrease (p = 0.273). This study indicated that there has been some improvement in the awareness of the proper use of SGLT2 inhibitors and there is still a need to continue enlightenment activities.