Hypoglycemia associated with off-label sitagliptin use

PURPOSE To describe a case of hypoglycemia induced by off-label use of sitagliptin in an adult patient with type 2 diabetes. CASE SUMMARY Addition of sitagliptin to metformin, glimepiride, and NovoLog(®) 70/30 Mix induced hypoglycemia in a 55-year-old Caucasian female. Hypoglycemia improved, although still occurred periodically, following sulfonylurea discontinuation and a 28% insulin dose reduction. Hypoglycemic symptoms were absent during a 3-day dechallange but occurred again upon sitagliptin reinitiation. DISCUSSION Although the mechanism of action of sitagliptin does not predispose patients to hypoglycemic events, when combined with hypoglycemia-inducing medications, eg, sulfonylureas or insulin, and possibly meglitinides, the incidence likely increases. CONCLUSIONS Caution should be used when combining sitagliptin with either sulfonylureas or insulin, and possibly meglitinides, for the treatment of type 2 diabetes as hypoglycemia may ensue. Hypoglycemia due to off-label combinations with insulin and sitagliptin may be prevented by reducing meal-time insulin doses. Prescribers and patients should vigilantly monitor for hypoglycemic events when using sitagliptin off-label with similar pharmacologic combinations such as meglitinides and other rapid-acting insulin products. Additionally, clinicians may encounter resistance from insurance companies to cover such off-label combinations.