Medication Error with High-Alert Drug: Insulin
A 70-year-old woman with type 2 diabetes is admitted with pneumonia. Her home insulin regimen is glargine 20 units at bedtime and lispro 5 units before meals. In the hospital, the physician orders "insulin glargine 20 units IV every morning" and "sliding scale insulin lispro before meals." The nurse administers the glargine IV. Two hours later, the patient becomes diaphoretic, confused, and has a blood glucose of 40 mg/dL. The pharmacy is asked to review the incident.
1. Identify the medication error and explain why it is dangerous.
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The error is the route of administration: insulin glargine is a long-acting basal insulin that should only be given subcutaneously, not intravenously. IV administration of glargine can cause unpredictable absorption and severe hypoglycemia because the depot formation is bypassed, leading to rapid and prolonged hypoglycemia. Additionally, the order was written as "IV" which is incorrect. The nurse administered as ordered without questioning, and the pharmacist did not catch the error during order verification. This is a high-alert medication error.
2. Describe the immediate treatment for hypoglycemia and propose system changes to prevent recurrence.
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Immediate treatment:
- For severe hypoglycemia with altered mental status: administer IV dextrose (e.g., 25 g of 50% dextrose) or glucagon 1 mg IM if no IV access.
- Recheck blood glucose in 15 minutes and repeat as needed.
- Once patient is alert, provide oral carbohydrate.
- Monitor blood glucose frequently and adjust insulin.
System changes:
- Implement a protocol for high-alert medications including insulin: standardized order sets, separate storage for IV and SC insulin, use of "units" not "U", and require pharmacist verification.
- Education for nursing and medical staff on insulin routes.
- Use of barcode medication administration.
- Encourage a "question the order" culture and double-checks for high-alert drugs.