SGLT2 Inhibitors in Combination Therapy: From Mechanisms to Clinical Considerations in Type 2 Diabetes Management

The progressive nature of type 2 diabetes (T2D) requires practitioners to periodically evaluate patients and intensify glucose-lowering treatment once glycemic targets are not attained. With guidelines moving away from a one-size-fits-all approach toward setting patient-centered goals and allowing flexibility in choosing a second-/third-line drug from the growing number of U.S. Food and Drug Administration-approved glucose-lowering agents, keen personalized management in T2D has become a challenge for health care providers in daily practice. Among the newer generation of glucose-lowering drug classes, sodium-glucose cotransporter 2 inhibitors (SGLT2is), which enhance urinary glucose excretion to lower hyperglycemia, have made an imposing entrance to the T2D treatment armamentarium. Given their unique insulin-independent mode of action and their favorable efficacy-to-adverse event profile and given their marked benefits on cardiovascular-renal outcome in moderate-to-high risk T2D patients, which led to updates of guidelines and product monographs, the role of this drug class in multidrug regimes is promising. However, despite many speculations based on pharmacokinetic and pharmacodynamic properties, physiological reasoning, and potential synergism, the effects of these agents in terms of glycemic and pleiotropic efficacy when combined with other glucose-lowering drug classes are largely understudied. In this perspective, we review the currently emerging evidence, discuss prevailing hypotheses, and elaborate on necessary future studies to clarify the potential risks and benefits of using an SGLT2i in dual combination with metformin and triple combination with a glucagon-like peptide 1 receptor agonist, dipeptidyl peptidase 4 inhibitor, or other glucose-lowering agent that is recommended by the American Diabetes Association and European Association for the Study of Diabetes (i.e., a sulfonylurea, thiazolidinedione, or insulin) to treat patients with T2D.