Safety and Tolerability of Sodium-Glucose Cotransporter-2 Inhibitors: A State-of-the-Art Narrative Review.

Sodium-glucose cotransporter-2 inhibitors (SGLT-2is) have evolved from glucose-lowering agents to foundational therapies for the management of type 2 diabetes mellitus, heart failure, and chronic kidney disease, with substantial benefits for cardiovascular, kidney, and survival outcomes. As their indications continue to expand, a comprehensive understanding of their safety and tolerability has become increasingly important for optimizing patient care. Building on our recent state-of-the-art review of glucagon-like peptide-1 receptor agonists, this review provides a contemporary synthesis of the evidence on the safety and tolerability of SGLT-2is. We critically appraise data from randomized controlled trials, cardiovascular and kidney outcome trials, pharmacovigilance databases, large observational studies, and systematic reviews and meta-analyses. The available evidence demonstrates that SGLT-2is have a favorable overall safety profile, with genital mycotic infections representing the most consistently observed adverse event. Volume depletion and euglycemic diabetic ketoacidosis remain clinically important but are uncommon and are largely preventable through appropriate patient selection, patient education, and temporary treatment interruption during high-risk clinical situations. Fournier's gangrene should be regarded as a very rare but serious complication requiring prompt recognition and treatment. In contrast, randomized trials and meta-analyses generally indicate a reduced risk of acute kidney injury, while evidence concerning fracture, lower-limb amputation, hepatotoxicity, pancreatitis, and cancer is less definitive. Although consistent class-wide increases in these latter outcomes have not been established, uncommon or agent-specific risks cannot be excluded, particularly where event numbers are small or follow-up is limited. Overall, treatment discontinuation because of adverse events is low across major cardiovascular, heart failure, and kidney outcome trials, supporting the excellent tolerability of this therapeutic class. Comparative evidence suggests only modest differences among individual SGLT-2is, although definitive conclusions remain limited by the absence of direct, large, randomized head-to-head trials. We also summarize practical strategies for adverse-event mitigation, monitoring, temporary treatment interruption, and individualized patient selection. As the clinical applications of SGLT-2is continue to broaden, ongoing pharmacovigilance, inclusive clinical trials, and comparative safety studies will be essential to further refine their benefit-risk profile and optimize their safe use across diverse patient populations.