Canagliflozin in Type 1 Diabetes: A Case Series of Patient Outcomes in a Diabetes Clinic

Abstract

Canagliflozin is a member of the sodium–glucose cotransporter 2 (SGLT2) inhibitor class and is approved by the U.S. Food and Drug Administration (FDA) for use in patients with type 2 diabetes as an adjunct to diet and exercise to improve glycemic control. Canagliflozin works by inhibiting SGLT2 in the proximal renal tubules, causing a reduction of filtered glucose reabsorption, lowering of the renal threshold for glucose, and increasing urinary glucose excretion (1).\n\nThe American Diabetes Association (ADA) Standards of Medical Care in Diabetes—2017 (2) and the American Association of Clinical Endocrinologists/American College of Endocrinology (AACE/ACE) (3) recommend SGLT2 inhibitors as add-on to metformin for patients with type 2 diabetes uncontrolled after 3 months of metformin use. The ADA lists the SGLT2 inhibitors as investigational agents for patients with type 1 diabetes because of the risk of diabetic ketoacidosis (DKA). Despite concerns for DKA in patients with type 2 diabetes treated with an SGLT2 inhibitor, a clinical review by an expert panel found that DKA occurred infrequently and recommended no change to their labeling (4). Although SGLT2 inhibitors are not FDA-approved for use in patients with type 1 diabetes, providers have prescribed these agents for off-label use in this patient population. Glycemic variability may be problematic in patients with type 1 diabetes; therefore, adding an SGLT2 inhibitor can assist in not only improving glycemic control but also reducing glycemic fluctuations. Although adding an SGLT2 inhibitor to insulin may increase the risk of hypoglycemia, the potential to reduce the need for increasing insulin doses may moderate this effect. Patients with type 1 diabetes uncontrolled with insulin therapy who are overweight/obese and have hypertension may benefit from the addition of an SGLT2 inhibitor because these medications help to lower A1C values and can reduce both weight and blood pressure.\n\nSeveral studies have …