RxNORM 101: What you need to know for clinical documentation

RxNORM® terminology identifies identical drugs listed by different names, an important need for healthcare. Learn more in this primer.
Clinical documentation

Table of Contents

What is RxNORM?

RxNORM is a system for normalizing the names of prescription and over-the-counter drugs. Identical medications – including generics and branded drugs – are often referred to by different names by different hospitals, pharmacies, and other organizations. Developed and maintained by the National Library of Medicine (NLM), RxNORM attempts to eliminate confusion by naming these drugs in a standardized format.

Why is the RxNORM system important?

It all comes down to interoperability. In order for health IT systems – like electronic health records (EHRs) – to communicate with one another, the data they send, receive, and process must be in standardized formats. Without RxNORM, the drug names used by an EHR in one facility might be unrecognizable to EHRs at other organizations. As patients move between organizations and work with different providers, this could have a negative impact on their care.

What do RxNORM codes look like?

The NLM creates RxNORM names and codes based on the drug names it receives from drug database sources like DrugBank, Multum MediSource Lexicon, and Micromedex RED BOOK. When different drug names have the same meaning, they’re grouped together under the same normalized codes.

Called RXCUIs, for RxNORM concept unique identifiers, these machine-readable codes allow computers to identify the drug in question regardless of how it’s named in various drug databases. The RXCUI 198013, for example, is used to identify 250 milligrams of orally administered Naproxen, while the source data for this drug and dosage includes names like Naproxen Tab 250 MG, NAPROXEN@250 mg@ORAL@TABLET, and Naproxen 250 MILLIGRAM In 1 TABLET ORAL TABLET. By contrast, 160 milligrams of acetaminophen as an oral capsule is identified with the RXCUI 307667, while 325 milligrams of the same medication in chewable-tablet form has the RXCUI 2264779.

RxNORM codes are updated every week with any newly approved drug information submitted to NLM from database sources.

Where is RxNORM data collected and stored beyond the EHR?

The NLM provides RxNORM data through the online files and software that are part of its free Unified Medical Language System (UMLS). To use the UMLS and its “Metathesaurus” browser, organizations must have a UMLS Terminology Services (UTS) account.

RxNORM is also available through an RxNORM API and an application called “RxNav”. The app allows organizations to easily search RxNORM data, and doesn’t require a license to use.

Beyond ensuring health IT interoperability, how else are RxNORM codes used?

While IT teams at healthcare organizations use RxNORM to facilitate communication between EHRs, the naming system has other applications as well. Insurance companies, for example, can use RxNORM to build the drug lists that are part of their prescription drug coverage policies, and researchers have relied on the system to code disparate medication data collected from study participants.

What’s the difference between RxNORM and the National Drug Code (NDC)?

The National Drug Code is the Food and Drug Administration’s (FDA’s) standard for identifying finished medications marketed for use in the United States. The NDC provides package-level information about specific drugs, and is used by healthcare organizations when submitting claims for covered medications. RxNORM, on the other hand, is simply a way to ensure there’s no ambiguity when it comes to identical medications that have different names. RxNORM involves name normalization, while the NDC is focused entirely on identification.

To learn more about medications and clinical documentation download our white paper, Labs, meds, and data quality: Taming complexity through normalization.

RxNorm® is a registered trademark of the National Library of Medicine.

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