Preventing U-100 and U-500 Insulin Mix-Ups: Pass This Information on to Your Doctor & Pharmacist
The non-profit Institute for Safe Medication Practices says there has been an increase in reports about mix-ups between prescriptions of insulin U-100 and insulin U-500 (U-500 is a concentrated insulin that is five times stronger than U-100).
The mistakes have occurred when prescribers have accidentally selected U-500 insulin from computer screens instead of U-100. The risk is that these errors can result in dangerous hyperglycemia or hypoglycemia.
ISMP has identified several possible reasons for these errors:
- Sometimes dosage forms for the two insulins appear one line apart on the screen, making it easy for a prescriber to select the wrong one.
- Depending on the screen size, the prescriber may see only the first few words of the product listing, so the drug concentration may not be visible.
- Since the use of U-500 insulin is not common at present, prescribers may just assume that the only regular insulin that’s available is U-100 and not even look for the concentration on the screen. (ISMP suggests that the use of U-500 insulin may be increasing due to the higher prevalence of obesity, the use of insulin pumps, and tight glucose control protocols in hospitalized patients.)
- If U-500 isn’t commonly used in a facility, the facility should consider listing it differently from other insulins, so it doesn't appear on the same screen as other insulin products.
- Consider adding a hard stop to all orders for U-500. This requires prescribers and pharmacists to verify that a patient should be getting the U-500.
- Pharmacies should consider not stocking U-500 if they don’t have patients who use it.