失智症及糖尿病均是目前高齡化社會常見之慢性疾病，糖尿病是失智症的危險因子，低血糖與失智症又具有雙向性之關聯。降血糖藥物於失智症糖尿病人之使用，合宜及穩定的控制其血糖，避免高血糖或低血糖等血糖異常波動情形，為其治療目標。失智糖尿病人之降血糖用藥原則除需評估藥效、服藥便利性與低血糖風險，還要考量簡明易於病人配合的給藥方式，以方便認知功能不良病人穩定地控制其血糖。各類口服降血糖藥物作用機轉、藥效表現、作用長短及副作用不同，用於失智糖尿病人之臨床效益及風險亦各異。對於認知功能不良糖尿病人而言，個人化合適的血糖控制及避免低血糖風險，比血糖的積極控制更為重要，優先考慮較不會有低血糖風險的口服降血糖藥物。

Dementia and diabetes are both commonly seen as chronic diseases in an aging society. Diabetes is a risk factor for dementia, and hypoglycemia and dementia also seem to have a bidirectional association. The goal of antidiabetic drugs used in diabetes with dementia is to maintain a normal level of blood sugar, avoid abnormal fluctuations between two extremes of being hyperglycemia or hypoglycemia. The principal considerations for choosing oral hypoglycemic medications for a diabetic patient with dementia include not only efficacy, accessibility, low hypoglycemic risks, but also easy-to-follow dosing regimen so that patients with cognitive dysfunction could easily achieve stable control of their blood sugar. The mechanism, efficacy, duration, and side effects of various oral hypoglycemic drugs are different, and their clinical benefits and risks for dementia patients are also distinct. For diabetic patients with cognitive dysfunction, personalized and manageable blood sugar control and avoiding hypoglycemia are more important than achieving blood glucose control aggressively. Therefore, antidiabetic drugs with a low risk of hypoglycemia should be considered first.