Evaluation of RxNorm in Ambulatory Electronic Prescribing

Drug prescriptions need to accurately identify the medications that prescribers intend for pharmacists to dispense. However, the set of computer-interpretable identifiers currently used in electronic prescribing (e-prescribing) does not support the specific needs of the prescribers and pharmacists who conduct e-prescribing transactions. RxNorm, a drug nomenclature from the National Library of Medicine, assigns a rigorously derived, centrally maintained, and publicly available unique identifier to each clinically distinct drug. It therefore has the potential to greatly improve drug identification in e-prescribing transactions. Through laboratory research and pilot testing, the authors evaluated RxNorm's potential to improve how medications are represented in e-prescribing transactions. They found that RxNorm is highly complete for prescription drugs used in ambulatory practice that are within its scope and that it offers substantial efficiency and parsimony gains for communicating health plan formulary information to prescribers. The errors that arose during use were of low clinical significance. In live pilot testing, RxNorm identifiers were successfully added to prescription transactions sent between participating prescribers and pharmacies, and the pharmacies were able to use this information to check for dispensing errors or to disambiguate prescriptions. The authors found that RxNorm appears to provide drug identifiers that more accurately reflect the prescriber's intent than the drug identifier set currently used.