RxNorm in MEDITECH 6.0

Introduction

RxNorm is a standardized naming convention for generic and branded drugs, which is designed to allow for interoperability between different electronic healthcare systems. The National Library of Medicine (NLM), a part of the US Department of Health and Human Services, is responsible for the content of RxNorm. The NLM updates RxNorm content on a monthly basis.

Structure

RxNorm uses a naming process, which can be broken down into five different steps. The first step of this process is to condense many synonyms into unique concepts. All of the synonyms mean the same thing at a certain level. For example: Acetaminophen 250mg tablet, Acetaminophen 250mg in 1 ORAL TABLET, and ACETAMINOPHEN@250mg@ORAL@TABLET are all describing the same concept at one level. Once a number of synonyms have been grouped they can be given a “normalized” name.

Approximately 60% of the concepts will be given a normalized name. The remainder of the concepts will not be given a normalized name because they are too ambiguous to be grouped under one name. The fully specified name takes the form: “Ingredient Strength Form”. For example: Acetaminophen 250mg Tablet. The fully specified name for a branded medication adds the brand name to the end. For example: Acetaminophen 250mg Tablet Tylenol. After the concept is assigned a fully specified name, it is assigned an RxNorm Concept Unique Identifier (RXCUI). An RXCUI is a computer- readable numeric code used to identify a specific RxNorm concept. Drugs can share RXCUIs, but any drug mapped to that code is expected to be identical in ingredient, dose, and form. The drugs associated to the RXCUI can have different characteristics, but must be identical in those criteria.

Once the concept has been assigned an RXCUI, other information is culled from the source data for establishing relationships based on synonyms, ingredients, and other reference points. RxNorm is a terminology which incorporates its data from several different terminologies including FDA databases, the Gold Standard Drug Databases, SNOMED-CT, and others. These databases contain overlapping information, but also additional information such as National Drug Codes (NDCs) for example.

The information gathered from the multiple databases and terminologies are incorporated into RxNorm via relationships. A relationship in RxNorm can take many different forms. When the concept's fully specified name is created, a number of additional names are built as well. These names vary based on their level of specificity. For example: “Acetaminophen” could be one of these associated names. In that example all that one can determine is the ingredient. The relationship linking this example to the fully specified name might take the form “Acetaminophen INGREDIENT_OF Acetaminophen 250mg Tablet”. RxNorm relationships also link drugs by form, strength, and “is-a relationships” (e.g.: Acetaminophen 250mg Tab IS-AN Acetaminophen Tab)

Usage within the MEDITECH EHR

RxNorm will be adopted into the MEDITECH EHR to meet requirements set by ARRA. RXCUI codes and RxNorm standardized names will be stored within an MIS Nomenclature dictionary and then linked the Pharmacy Drug dictionary. These RXCUI codes will then be sent in the Continuity of Care Document (CCD) to provide a standardized output, which can be universally interpreted.

Table in livefdb

[dbo].[MisNomenclatureMap_RxNormCode].MisNomenclatureMapID

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