Error Alert
Institute for Safe Medication Practices, Horsham, PA
Because of the similarity among names of insulin products, searching by generic name for rapid-acting insulins may result in prescribing or dispensing the incorrect product. Although safety would be improved if the manufacturers and FDA examined ways to better communicate product differences through nomenclature, labeling, and/or packaging changes, pharmacists must be prepared to provide the correct medication to patients.
The differences
Medication errors have been reported due to mix-ups between Novo Nordisk’s Fiasp and NovoLOG, as well as the company’s authorized generic for NovoLOG, all of which are insulin aspart. However, Fiasp has niacinamide in the formulation, which makes it even faster acting than NovoLOG.
The same problem exists with Lilly’s newly marketed Lyumjev, HumaLOG, and the company’s authorized generic for HumaLOG, all of which are insulin lispro. Lyumjev (insulin lispro-aabc) contains treprostinil and other ingredients that make the product faster acting than HumaLOG.
These products have different onsets of action after S.C. injection and are not substitutable. Fiasp and Lyumjev are injected at the beginning of a meal or within 20 minutes after beginning a meal. Other insulin lispro products (e.g., HumaLOG) are given within 15 minutes before a meal or immediately after; other insulin aspart products (e.g., NovoLOG) are given 5 to 10 minutes before a meal.
However, some prescribers and pharmacists may not be aware of the difference between these insulin products. For example, if insulin aspart is prescribed, it may result in dispensing either NovoLOG (or the authorized generic) or Fiasp if the brand name is not included on the prescription.
This is what happened in one event reported to the Institute for Safe Medication Practices. A prescriber ordered Fiasp for a patient and submitted the prescription to the pharmacy electronically. Although he selected Fiasp, the product name included as the e-prescribing drug name (EPN) was the nonproprietary name “insulin aspart.” The brand name was not included in the prescription, and the pharmacy dispensed NovoLOG.
Safe practice recommendations
Computer listings should always include the brand name for these insulins. A pharmacist who recently reported the potential for mix-ups also recommended including niacinamide in parentheses with Fiasp listings and treprostinil in parentheses for Lyumjev listings.
When composing and transmitting an electronic prescription, there should be only one name communicated as the EPN—either the brand name or the generic name of the product. When there is no generic product commercially available, the brand name of the available product should be included as the EPN. The EPN must clearly reference either a brand or a generic product to enable the pharmacy computer system and pharmacy staff to determine the specific medication intended and ordered by the prescriber.
If the prescribed drug is available only as a brand product, the representative NDC, RxNorm code, and RxNorm qualifier transmitted with the prescription also must align to that of the brand name EPN. For example, when prescribing Fiasp and Lyumjev, prescribers should use the appropriate brand name on prescriptions, and electronic prescribing systems should communicate that brand name instead of only including the generic name.
Patients should be made aware of the differences between these and other insulins and know which product is intended for them. Teach patients to identify that the correct insulin has been dispensed by their pharmacist.