U-500 Regular Insulin

OBJECTIVE To describe the clinical experience and the pharmacokinetics of U-500 regular insulin in severely insulin-resistant obese type 2 diabetic patients. RESEARCH DESIGN AND METHODS Patients requiring >200 units of insulin with A1C levels >8.0% were switched to U-500 regular insulin. For the pharmacokinetic study, fasting subjects received 100 units of U-500 regular insulin subcutaneously, and samples drawn before and every 30-60 min for glucose, insulin, and C-peptides until glucose fell below 100 mg/dl. RESULTS U-500 regular insulin doses were adjusted using the same approach as for adjusting NPH insulin doses. Mean values at baseline and at minimum A1C levels were, respectively, A1C 9.9 and 7.1%, 3.2 and 3.3 units/kg, and weight 98.6 and 102.8 kg. Pharmacokinetically, insulin concentrations rose briskly by 30 min and remained elevated for at least 7 h. CONCLUSIONS Uncontrolled severely insulin-resistant obese type 2 diabetic patients can be satisfactorily controlled with U-500 regular insulin.