ABSTRACT
PURPOSE: The efficacy and safety of and key clinical considerations for using U-500 insulin human regular in the treatment of high-dose insulin-treated patients in a wide variety of settings are examined. SUMMARY: U-500 regular insulin has been available in the United States since 1952, but only recently has it become more commonly prescribed for patients requiring large amounts of insulin to improve their blood glucose control. This use coincides with the increasing rates of obesity and type 2 diabetes associated with significant insulin resistance, which can necessitate the need for doses of insulin exceeding 200 units/day. However, many health care professionals are relatively unfamiliar with this concentrated insulin formulation. U-500 regular insulin has a pharmacokinetic and pharmacodynamic profile that differs from U-100 human insulins and analogues. Although no randomized clinical trials using U-500 insulin have been performed, eight case series (involving 160 patients) have been published. Rare or infrequent occurrences of hypoglycemia with U-500 insulin have been reported. Of the medication errors associated with U-500 insulin, administration and dispensing errors occurred most frequently. With the increase in prescribing of U-500 insulin, pharmacists must be aware of the complex issues involved with appropriate prescribing, dispensing, and provision of patient education to maximize patient safety and avoid administration errors and dosing confusion. CONCLUSION: U-500 insulin is efficacious and safe for patients with type 2 diabetes who require a high dosage of insulin to control hyperglycemia. However, health care professionals should be well educated and vigilant about patient safety issues regarding the drug's prescription, dosing, and administration.