Recombinant human erythropoietin dosing errors due to concentrated EPO

Recombinant human erythropoietin (rHuEPO) is widely used to treat anemia. A dialysis provider enacted a policy utilizing 20,000 U/ml multi-dose vials for rHuEPO dosing. The purpose of this study was to determine the accuracy and precision in administering small rHuEPO doses from this vial.

Ten registered nurses (RNs) were selected at random, supplied with a rHuEPO vial refilled with water, and instructed to withdraw the following amounts (1,200 U, 2,400 U, 3,600 U) using standard procedures and assuming the standard rHuEPO concentration of 20,000 U/ml. Samples were drawn up in duplicate and placed into 1.5 ml micro-centrifuge tubes. The volumes were measured using P-100 or P-200 microliter pipettes. The equivalent amount of rHuEPO was calculated by multiplying the volume by 20 U/microl.

The rHuEPO dosing errors were large and on occasion greater than 100% at the 1,200 U dose. The variability for each RN, while large, was less than the inter-RN variability (within-RN % error 9.6% vs. 29.8% between-RN % error at the 1,200 unit dose). Errors occurred in both directions, both under- and overdosing.

Utilizing concentrated rHuEPO resulted in significant dosing errors at low rHuEPO doses. The implications include inaccurate medication administration and disparity between administered and billed dosages. Policy decisions that effect medication administration need to be carefully evaluated to determine their impact on patient well-being and safety.