Understanding RxNorm drug database
Understanding RxNorm drug database
Overview
RxNorm is a system of drug nomenclature managed by the U.S. National Library of Medicine (NLM) that enables the communication of drug data between electronic health systems, such as electronic medical records used by healthcare providers to manage patient clinical information. Other use cases for RxNorm are described below.
In today’s drug market there are many systems used to classify and manage drug data. For example, National Drug Codes (NDC) are managed by the U.S. FDA, and include data such as generic and brand names, ingredients, dosages, manufacturer, and packaging information. Also, databases such as First Data Bank and Medi-Span provide drug pricing information for each NDC, and information on drug interactions is managed through such systems as DrugBank and ONCHigh. RxNorm links its drug names to multiple drug data systems to support interoperability, or the effective communication among the disparate clinical data repositories using a common, or normalized vocabulary.
RxNorm structure
Every drug in the U.S. market is assigned a discrete number within the RxNorm catalogue, called an RxCUI, which identifies the drug’s active ingredients, strength, and form. Since a single drug can have multiple combinations of ingredients, strengths and forms each combination carries its own unique RxCUI. For example, the active ingredient in the brand name drug Tylenol is acetaminophen. Since there are greater than 50 combinations of acetaminophen strengths and forms in the market, there are as many RxCUIs associated with acetaminophen (see sample below).
Active Ingredient | Strength | Form | RxCUI |
acetaminophen | 160mg | Oral capsule | 307667 |
acetaminophen | 325mg | Chewable tablet | 2264779 |
acetaminophen | 500mg | Oral powder | 2374350 |
acetaminophen | 80mg | Disintegrating oral tablet | 251374 |
The RxNorm database is made up of 9 data tables that link each RxCUI to a wide range of drug information, including such elements as ingredients, brand name, clinical drug component and dosage information (see list below). The user begins a search for a drug in the RxNorm database by entering a drug’s identifier (e.g., name, RxCUI, NDC, HCPCS) into a search engine, such as the U.S. NLM’s RxNAV. A single search yield multiple results based on the information contained in those data tables. Those results organized as follows:
Ingredients | Brand name |
Brand drug or pack | Branded drug component |
Branded dose of form group | Clinical drug component |
Clinical dose form group | Clinical drug or pack |
Dosage form group |
Use cases
RxNorm supports a wide range of use cases. For example, as indicated above RxNorm supports the sending and retrieval of normalized drug data during the exchange of information between electronic health records and other clinical data repositories. In addition, RxNorm supports the identification of drug data used to build drug lists that can be incorporated into prescription drug coverage rules, prior authorizations, and drug formularies. And, each of those objects are typically used for claims adjudication, benefit configuration, and care management protocols.
RxNorm in Pega Foundation for Healthcare
The Pega Foundation for Healthcare includes an RxNorm search capability in its Drug datastore layer. By logging into the Foundation and navigating to the Drug datastore portal, the user may select the Search RxNorm tab at the top of the landing page and initiate a query by selecting the format (string, NDC, ANDA, RxCUI, AMPID, or HCPCPS) in the left-hand dropdown, entering the required information in the right-hand field, and then clicking on the search button. The RxNorm search engine then returns data specific to the user's selection referencing the tables identified above.