Use of U-500 insulin in continuous subcutaneous insulin infusion in a patient with severe insulin resistance

Abstract

U-500 insulin (Humulin R; Eli Lilly, Indianapolis, Indiana, USA) is five times as concentrated as conventional U-100 insulins. We report the case of a woman with marked insulin resistance in whom the use of U-500 insulin in continuous subcutaneous insulin infusion (CSII) resulted in a marked improvement. Benefits included improved glycated haemoglobin A_1C, decreased volume of insulin required, fewer reservoir changes, greater patient satisfaction and cost savings. We discuss the characteristics of U-500 insulin and how it can be an important option in the treatment of patients on CSII who have marked insulin resistance and a high daily insulin requirement.