Based on many reports, an unmistakable link probably exists between diabetes mellitus and COVID-19. A major predisposing factor determining severity and mortality of COVID-19 is diabetes mellitus, diabetic patients were shown to be at higher risk for developing severe COVID-19 disease than non-diabetics; many recent studies reported a striking prevalence of DM in those diagnosed with COVID-19. Accordingly, antidiabetic drugs can possibly impact the clinical course and / or the outcome of this infection, either by alleviating diabetes-associated symptoms, minimizing its complications, or by mitigating or aggravating COVID-19 disease by effects independent from their direct antidiabetic effects. Several antidiabetic drug classes were shown to have varying effects, like blocking viral entry to cells, as well as having immunomodulatory, anti-inflammatory, antifibrotic, or cardioprotective effects; such effects could prove beneficial for COVID-19 patients. On the other hand, some antidiabetic agents may have adverse effects that aggravate patients’ condition like hypoglycemia, fluid retention, increased weight or lactic acidosis, which require special consideration in patient management. Some of the drugs were found in observational studies to either reduce mortality from COVID-19 or pose no harm, but more solid evidence from clinical trials is still lacking.

Keywords: COVID-19; diabetes; DPP4 inhibitors; metformin; SGLT2 inhibitors; sulfonylureas; thiazolidinediones