Strategies to Prevent Five-Fold Wrong Dose Errors With U-500 Insulin

Over the years, the Patient Safety Authority (PSA) has highlighted numerous errors involving insulin. [1][2]2][3][4][5] Recently, PSA has received several reports via the Pennsylvania Patient Safety Reporting System (PA-PSRS) describing errors with U-500 insulin that led to patients receiving either five times less or five times more insulin than intended.Humulin R U-500, a type of insulin that is five times more concentrated than U-100 insulin, is used to manage blood glucose levels in individuals with diabetes mellitus requiring more than 200 units of insulin per day. 6,7As a high-alert medication, 8 U-500 insulin has been associated with dose errors that can lead to life-threatening hypoglycemia or hyperglycemia. 6ere are many ways in which wrong dose errors can occur with insulin.The unique measurement system of insulin using "units" instead of the conventional milliliter (e.g., 1 mL=100 units) inherently complicates its dosing. 2,3,5The potential for errors is further amplified by the availability of various formulations, concentrations, and delivery devices. 1,2,7,[9][10]0][11][12][13][14] In the recent PA-PSRS reports, fivefold wrong dose errors with U-500 insulin occurred after the patients' home dose of insulin was incorrectly reconciled during admission to facilities that use 1 mL tuberculin or U-100 syringes to administer U-500 insulin.Presently, the U.S. Food and Drug Administration advises that U-500 insulin should only be administered using specifically designed U-500 syringes. 15