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Unified Medical Language System® (UMLS®)

RxNorm Overview

This overview is intended to give new users a general idea of the purpose and structure of RxNorm. The RxNorm technical documentation contains a more-detailed explanation of the technical aspects of RxNorm.

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What is RxNorm?

RxNorm is two things: a normalized naming system for generic and branded drugs; and a tool for supporting semantic interoperation between drug terminologies and pharmacy knowledge base systems. The National Library of Medicine (NLM) produces RxNorm.

Purpose of RxNorm

Hospitals, pharmacies, and other organizations use computer systems to record and process drug information. Because these systems use many different sets of drug names, it can be difficult for one system to communicate with another. To address this challenge, RxNorm provides normalized names and unique identifiers for medicines and drugs. The goal of RxNorm is to allow computer systems to communicate drug-related information efficiently and unambiguously.

Scope of RxNorm

RxNorm contains the names of prescription and many over-the-counter drugs available in the United States. RxNorm includes generic and branded:

  • Clinical drugs - pharmaceutical products given to (or taken by) a patient with therapeutic or diagnostic intent
  • Drug packs - packs that contain multiple drugs, or drugs designed to be administered in a specified sequence

Radiopharmaceuticals, bulk powders, contrast media, food, dietary supplements, and medical devices, such as bandages and crutches, are all out of scope for RxNorm.

How is RxNorm produced?

NLM receives drug names from many data sources, analyzes and processes the data, and outputs the data into RxNorm files in a standard format. There are many steps involved in RxNorm production, but these five basic steps give a general idea of how RxNorm is produced:

1. Group source data into collections of synonyms (called concepts).

Sample source data:

  • Naproxen Tab 250 MG
  • Naproxen 250mg tablet (product)
  • NAPROXEN@250 mg@ORAL@TABLET
  • Naproxen 250 MILLIGRAM In 1 TABLET ORAL TABLET
  • NAPROXEN 250MG TAB,UD [VA Product]

Sources format their drug names in many different ways. Although the drug names in this Naproxen example appear different, they all have the same meaning at a certain level of abstraction. RxNorm groups these as synonyms into one concept.

2. Create an RxNorm normalized name for each concept (if the concept is in scope and unambiguous).

About 60% of the drug names from source vocabularies receive RxNorm normalized names in addition to the names provided by the source vocabularies. The other 40% do not receive RxNorm normalized names, because they are either out of scope or their names are too ambiguous. The most common types of names that are not assigned RxNorm normalized names are medical devices, foods, and enzymes.

The Naproxen concept above is in scope for RxNorm, so it is assigned an RxNorm normalized name. The normalized name consists of the ingredient, strength, and dose form (in that order) for fully-specified generic drugs. In our example, the RxNorm normalized name is 'Naproxen 250 MG Oral Tablet'. The branded version of this drug uses the same format but includes the brand name in brackets at the end (e.g., 'Naproxen 250 MG Oral Tablet [Prosaid]').

3. Assign an RxNorm concept unique identifier (RXCUI) to each concept and an RxNorm atom unique identifier (RXAUI) to each atom.

Each concept receives an RXCUI, which is unique to that concept. An RXCUI is essentially the "name" of a concept that computers read and understand. RXCUIs are never deleted or reused; RXCUIs and the meanings of concepts persist from one RxNorm release to the next.

Concepts are collections of synonyms at a given level of abstraction. Each drug name carries additional characteristics, including its source, its code (the unique identifier assigned by its source), and its term type (described below). An atom is a drug name plus these additional characteristics. Each atom within a concept receives an atom unique identifier, an RXAUI.

NLM assigns the RXCUI '198013' to the Naproxen concept above. Each of the atoms associated with the drug names listed above receives a separate RXAUI.

4. Include relationships and attributes from the source data.

Source data include more than drug names in some cases. Data can also include relationships that link drug names to other drug names and ingredients, as well as other information, such as National Drug Codes (NDCs), marketing categories, and pill imprint information.

Using the same example as before, you'll find relationships to synonyms and ingredients, as well as NDC, manufacturer, and pill size attributes.

5. Create related RxNorm names and relationships.

In addition to the fully complete clinical drug names (ingredient, strength, and dose form), RxNorm also creates names at other levels of specificity:

  • ingredient / precise ingredient / multiple ingredients
  • ingredient + strength
  • ingredient + dose form / ingredient + dose form group

Whenever NLM creates a fully-specified drug name, these more general names (and the concepts that contain these names) are also created if they don't already exist. RxNorm then creates relationships to link these concepts together. This set of concepts and relationships is a "graph." So for both generic and branded drugs, RxNorm "fills out the graph" by creating the related drug names (and their concepts) that don't already exist. In the case of branded drugs, NLM creates their generic counterparts when they don't already exist in the data.

Along with the RxNorm fully-specified name 'Naproxen 250 MG Oral Tablet', NLM creates:

  • 'Naproxen'
  • 'Naproxen 250 MG'
  • 'Naproxen Oral Tablet' / 'Naproxen Oral Products' / 'Naproxen Pills'

RxNorm links these names using relationships. Here are a few examples:

  • 'Naproxen 250 MG Oral Tablet' has_dose_form 'Oral Tablet'
  • 'Naproxen' ingredient_of 'Naproxen 250 MG'
  • 'Naproxen 250 MG Oral Tablet' isa 'Naproxen Oral Tablet'
  • 'Naproxen Pills' has_ingredient 'Naproxen'

Where does RxNorm get its data?

RxNorm data sources

RxNorm is a terminology built on and derived from other terminologies. RxNorm reflects and preserves the meanings, drug names, attributes, and relationships from its sources. RxNorm receives drug names from 14 source terminologies:

SourceSource Abbreviation (SAB)
Anatomical Therapeutic Chemical Classification System ATC
Gold Standard Drug Database GS
Medi-Span Master Drug Data Base MDDB
Medical Subject Headings (MeSH) MSH
Multum MediSource Lexicon MMSL
Micromedex RED BOOK MMX
FDA National Drug Code Directory MTHFDA
FDA Structured Product Labels MTHSPL
FDB MedKnowledge (formerly NDDF Plus) NDDF
Veterans Health Administration National Drug File - Reference Terminology NDFRT
NDFRT FDASPL relationships NDFRT_FDASPL
NDFRT FMTSME relationships NDFRT_FMTSME
US Edition of SNOMED CT (drug information) SNOMEDCT_US
Veterans Health Administration National Drug File VANDF

 

If a drug name isn't included in the RxNorm data files, then RxNorm didn't receive this information from any of its data sources.

SAB=RXNORM

In addition to the 14 data sources, the derived RxNorm normalized drug names become a terminology. RxNorm is composed of the normalized names based upon the information received from the sources listed above. We'll refer to these normalized names as SAB=RXNORM so it's clear when we are talking about RxNorm as a set of drug terminologies (RxNorm) and RxNorm as a source of normalized drug names (SAB=RXNORM).

Each SAB=RXNORM normalized name follows a simple pattern using the ingredient, strength, and dose form. For branded drugs, SAB=RXNORM includes the brand name, and for packs of drugs, SAB=RXNORM includes the quantities of each drug.

Generic drugs Ingredient Strength Dose Form
Branded drugs Ingredient Strength Dose Form [Brand Name]
Generic drug packs {# (Ingredient Strength Dose Form) / # (Ingredient Strength Dose Form)} Pack
Branded drug packs {# (Ingredient Strength Dose Form) / # (Ingredient Strength Dose Form)} Pack [Brand Name]

 

Ingredient: Ingredients generally use the United States Adopted Name (USAN). The Basis of Strength Substance (BoSS) is used in the fully normalized name (e.g., warfarin sodium vs warfarin in 'Warfarin Sodium 1 MG Oral Tablet').

Strength: SAB=RXNORM bases the strength on the active ingredient(s), which may be either the precise (salt or ester) or the base ingredient of the drug. Strengths use the "milli" metric system equivalents (e.g., milligrams, milliliters). Liquids are expressed per milliliter. When a powder can be reconstituted to a range of liquid concentrations, the highest concentration in the range is used for the normalized form.

Dose Form: SAB=RXNORM uses a set of dose forms based upon those included in the Health Level 7 (HL7) data standard.

Brand name: SAB=RXNORM usually represents brand names as seen on the packaging (e.g., Zoloft, Tylenol Cold Relief, and Advair 115/21). In cases where the name on the packaging includes extra information that represents information beyond ingredient or strength, SAB=RXNORM removes additional that information (e.g., Lamisil instead of Lamisil AT and Spiriva instead of Spiriva HandiHaler).

Note: There are some cases where the SAB=RXNORM normalized drug name includes additional elements. For instance, drugs containing multiple ingredients will have all ingredients listed. Another example is drugs using specific dose forms that require a quantity factor even though they are not RxNorm drug packs, such as the volume of drug in a prefilled syringe, number of actuations in a metered dose inhaler, or duration of action of an extended release capsule.

Term Types

SAB=RXNORM uses term types (TTYs) to indicate generic and branded drug names at different levels of specificity. The following table includes the full list of SAB=RXNORM term types.

TTYNameDescriptionExample
IN Ingredient A compound or moiety that gives the drug its distinctive clinical properties. Ingredients generally use the United States Adopted Name (USAN). Fluoxetine
PIN Precise Ingredient A specified form of the ingredient that may or may not be clinically active. Most precise ingredients are salt or isomer forms. Fluoxetine Hydrochloride
MIN Multiple Ingredients Two or more ingredients appearing together in a single drug preparation, created from SCDF. In rare cases when IN/PIN or PIN/PIN combinations of the same base ingredient exist, created from SCD. Fluoxetine / Olanzapine
DF Dose Form See Appendix 2 for a full list of Dose Forms. Oral Solution
DFG Dose Form Group See Appendix 3 for a full list of Dose Form Groups. Oral Liquid
SCDC Semantic Clinical Drug Component Ingredient + Strength Fluoxetine 4 MG/ML
SCDF Semantic Clinical Drug Form Ingredient + Dose Form Fluoxetine Oral Solution
SCDG Semantic Clinical Dose Form Group Ingredient + Dose Form Group Fluoxetine Oral Product
SCD Semantic Clinical Drug Ingredient + Strength + Dose Form Fluoxetine 4 MG/ML Oral Solution
BN Brand Name A proprietary name for a family of products containing a specific active ingredient. Prozac
SBDC Semantic Branded Drug Component Ingredient + Strength + Brand Name Fluoxetine 4 MG/ML [Prozac]
SBDF Semantic Branded Drug Form Ingredient + Dose Form + Brand Name Fluoxetine Oral Solution [Prozac]
SBDG Semantic Branded Dose Form Group Brand Name + Dose Form Group Prozac Pill
SBD Semantic Branded Drug Ingredient + Strength + Dose Form + Brand Name Fluoxetine 4 MG/ML Oral Solution [Prozac]
PSN Prescribable Name Synonym of another TTY, given for clarity and for display purposes in electronic prescribing applications. Only one PSN per concept. Leena 28 Day Pack
SY Synonym Synonym of another TTY, given for clarity. Prozac 4 MG/ML Oral Solution
TMSY Tall Man Lettering Synonym Tall Man Lettering synonym of another TTY, given to distinguish between commonly confused drugs. FLUoxetine 10 MG Oral Capsule [PROzac]
BPCK Brand Name Pack {# (Ingredient Strength Dose Form) / # (Ingredient Strength Dose Form)} Pack [Brand Name] {12 (Ethinyl Estradiol 0.035 MG / Norethindrone 0.5 MG Oral Tablet) / 9 (Ethinyl Estradiol 0.035 MG / Norethindrone 1 MG Oral Tablet) / 7 (Inert Ingredients 1 MG Oral Tablet) } Pack [Leena 28 Day]
GPCK Generic Pack {# (Ingredient + Strength + Dose Form) / # (Ingredient + Strength + Dose Form)} Pack {11 (varenicline 0.5 MG Oral Tablet) / 42 (varenicline 1 MG Oral Tablet) } Pack
Relationships

SAB=RXNORM uses relationships to link concepts that contain the same ingredient or dose form. Using these relationships, you can navigate the SAB=RXNORM graph from an ingredient to a fully-specified drug and so forth. See Appendix 1 for a full list of relationships.

StringRelationship
Attribute
String
Acetaminophen 325 MG Oral Tablet has_tradename Acetaminophen 325 MG Oral Tablet [Tylenol]
Acetaminophen part_of Acetaminophen / Diphenhydramine
Acetaminophen 325 MG Oral Tablet [Tylenol] has_dose_form Oral Tablet
Oral Tablet dose_form_of Acetaminophen 325 MG Oral Tablet [Tylenol]

Most SAB=RXNORM relationships exist between concepts, which means they link one RXCUI to another RXCUI. There are also SAB=RXNORM relationships that link RXAUIs to other RXAUIs. These atom-level relationships link synonyms (TTY=SY, TTY=TMSY) to other SAB=RXNORM names within the same concept.

NDCs, UNIIs, and other attributes

In addition to normalized names and relationships, SAB=RXNORM includes attributes, which are additional pieces of information associated with a concept or an atom. For example, SAB=RXNORM associates unique ingredient identifiers (UNIIs) with concepts using the "UNII_CODE" attribute. Fully-specified drugs have other attributes, including NDCs. When source providers include NDCs in their data, SAB=RXNORM normalizes these NDCs to the 11-digit HIPAA format and adds them as attributes. For a full list of SAB=RXNORM attributes, see Appendix 4. Here are some attribute examples:

Attribute
Name (ATN)
Attribute
Value (ATV)
NDC 54569520800
NDC 58016082683
UNII_CODE 01K63SUP8D
RXN_HUMAN_DRUG US

How are the RxNorm data organized?

The full monthly RxNorm release includes 12 data files, which are simple text files with pipe ('|') delimiters between each field value. RxNorm data files are meant to be loaded as separate tables into a database management system. However, the files are not fully normalized as would be the case in a formal database; there are duplications across and within files by design.

Drug names and unique identifiers - RXNCONSO.RRF

RXNCONSO contains all of the source-provided drug and ingredient names, as well as the normalized SAB=RXNORM names. Each name is related to its RxNorm atom unique identifier (RXAUI), RxNorm concept unique identifier (RXCUI), source vocabulary (SAB), and term type (TTY). Each row in this file represents a single atom, and the RXAUI value is unique for each row. Essentially, the row is the atom. Because a given concept may include multiple atoms, there may be multiple rows with a given RXCUI.

Sample data from RXNCONSO:

141962|ENG||||||2407920||||NDDF|CDD|016630|AZITHROMYCIN@250 mg@ORAL@CAPSULE (HARD, SOFT, ETC.)||O||
141962|ENG||||||3104225||N0000158075||NDFRT|PT|N0000158075|AZITHROMYCIN 250MG CAP||O||
141962|ENG||||||2403354||||MMX|CD|125011|Azithromycin 250 MG Oral Capsule||N||
141962|ENG||||||944489|944489|141962||RXNORM|SCD|141962|Azithromycin 250 MG Oral Capsule||N|4096|
141962|ENG||||||944502||324252006||SNOMEDCT|FN|324252006|Azithromycin 250mg capsule (product)||N||
141962|ENG||||||944496||||VANDF|CD|4010157|AZITHROMYCIN 250MG CAP||O||

These six rows of data represent synonymous drug names from the same concept. This concept has the normalized SAB=RXNORM name 'Azithromycin 250 MG Oral Capsule' and the RXCUI '141962' (as shown in the first column of the data). The RXAUIs for each of these atoms are different (as shown in the column of numbers that starts with '2407920').

Synonymous atoms are grouped into concepts, even if they don't receive a normalized SAB=RXNORM name:

62959|ENG||||||565933||||MDDB|CD|06986|Cotton Balls||N||
62959|ENG||||||2364317||||MMSL|MS|NOCODE|Cotton Balls||N||
62959|ENG||||||2627757||||VANDF|IN|4024474|COTTON BALL||N||

Notice that there is no SAB=RXNORM normalized name for this out-of-scope concept; however, the concept does have an RXCUI ('62959').

Relationships - RXNREL.RRF

RXNREL contains all of the relationships that exist between atoms and between concepts. This includes source-provided relationships and relationships between SAB=RXNORM drug names.

Relationships in this file connect RXAUIs or RXCUIs. The corresponding drug names for these RXAUIs and RXCUIs are found in RXNCONSO.

Sample data from RXNREL:

141962||CUI|RN|105259||CUI|tradename_of|4170244||RXNORM||||N||
141962||CUI|RO|315449||CUI|constitutes|4252583||RXNORM||||N|4096|
141962||CUI|RO|316965||CUI|dose_form_of|4440822||RXNORM||||N|4096|
141962||CUI|RB|370974||CUI|inverse_isa|4380721||RXNORM||||N|4096|
----------------------------------------------------------------------------
105259||CUI|RB|141962||CUI|has_tradename|3981738||RXNORM||||N||
315449||CUI|RO|141962||CUI|consists_of|3993083||RXNORM||||N|4096|
316965||CUI|RO|141962||CUI|has_dose_form|4136890||RXNORM||||N|4096|
370974||CUI|RN|141962||CUI|isa|4139458||RXNORM||||N|4096|

SAB=RXNORM relationships exist between atoms and between concepts (as shown above), while source-provided relationships only exist between atoms from that source. SAB=RXNORM relationships are bi-directional. In the sample data, you can see one direction of relationships above the dividing line and relationships going in the opposite direction below the line. You can find a full list of SAB=RXNORM relationships with examples in Appendix 1.

Attributes - RXNSAT.RRF

RXNSAT contains all of the attribute data. This includes SAB=RXNORM attributes, such as normalized 11-digit NDCs, UNII codes, and human or veterinary usage markers, and source-provided attributes, such as labeler, definition, and imprint information. Each attribute has an 'Attribute Name' (ATN) and 'Attribute Value' (ATV) combination. For example, NDCs have an ATN of 'NDC' and an ATV of the actual NDC value.

RXNSAT associates attribute data with RXAUIs and RXCUIs. The corresponding drug names for these RXAUIs and RXCUIs are found in RXNCONSO.

Sample data from RXNSAT:

141962|||944489|AUI|141962|||RXN_HUMAN_DRUG|RXNORM|US|N|4096|
141962|||944496|AUI|4010157|AT54398167||VA_GENERIC_NAME|VANDF|AZITHROMYCIN|N||
141962|||944496|AUI|4010157|||NDC|VANDF|000069305034|O||
141962|||3104227|SCUI|N0000158075|||VUID|NDFRT|4010157|N||
141962|||2403354|AUI|125011|||DRT|MMX|Oral|N||

Semantic types - RXNSTY.RRF

RXNSTY contains the semantic types, or broad subject categories, assigned to each concept. Every concept receives at least one semantic type. 80% of RxNorm drug concepts have the semantic type 'Clinical Drug'.

RXNSTY associates semantic type data with RXCUIs. The corresponding drug names for these RXCUIs are found in RXNCONSO.

Sample data from RXNSTY:

141962|T200|A1.3.3|Clinical Drug||4096|
902046|T074|A1.3.1|Medical Device|||
860665|T200|A1.3.3|Clinical Drug|||
98220|T126|A1.4.1.1.3.3|Enzyme|||
98220|T116|A1.4.1.2.1.7|Amino Acid, Peptide, or Protein|||

Visit the UMLS Reference Manual for more information on semantic types and the Semantic Network.

Data history - RXNCUI.RRF, RXNCUICHANGES.RRF, RXNATOMARCHIVE.RRF

RXNCUI, RXNCUICHANGES, and RXNATOMARCHIVE include history information about RxNorm atoms and concepts.

RXNCUI contains information on retired concepts. A concept is retired when it:

  • merges into another concept or
  • has been renamed as a result of an error.

Sample data from RXNCUI:

283295|RXNORM_04AC_050210F|RXNORM_09AA_090908F|1|283295|
763070|RXNORM_09AB_100104F|RXNORM_09AB_100104F|1|763070|
197991|RXNORM_09AB_100301F|RXNORM_09AB_100301F|1|311752|

RXNCUICHANGES contains information on atoms that have changed concepts from the previous release to the current release. This file is not cumulative.

Sample data from RXNCUICHANGES:

1419457|4003569|VANDF|CD|DOXORUBICIN HCL 150MG/VIL (RDF) INJ|310024|1191138|
||RXNORM|||755184|1190348|
1260130|318192009|SNOMEDCT|PT|Atropine sulfate 600micrograms/1mL injection|245349|1190787|
2302994|1117536|RXNORM|OCD|Potassium Nitrate/Silver Nitrate 25%-75% Topical Swab|259286|1117536|

RXNATOMARCHIVE contains information about SAB=RXNORM atoms that are no longer in RXNCONSO.

Sample data from RXNATOMARCHIVE:

1353682|A10409371|Ascorbic Acid 100 MG / Zinc 13.3 MG Lozenge|10/01/2009 01:10:55 PM|03/10/2005 02:03:58 PM|09/29/2009 06:09:06 PM|283295||ENG|08-SEP-09||RXNORM_09AA_090908F|283295|RXNORM|SCD|283295|
2007378|A7238781|SULFAMETHOXAZOLE/TRIMETHOPRIM 80-16MG/ML INTRAVEN. AMPUL (ML)|06/23/2008 02:06:07 PM|03/10/2005 03:03:03 PM|06/10/2008 02:06:09 PM|313137||ENG|02-JUN-08||NDDF_2008_05_09|313137|RXNORM|OCD|313137|

Obsolete data - RXNCONSOOCD.RRF, RXNSATOCD.RRF, RXNSTYOCD.RRF

The obsolete clinical drug (OCD) files contain information on obsolete drug names. A name becomes obsolete when a source no longer provides that name. RXNCONSOOCD, RXNSATOCD, and RXNSTYOCD follow the same format as RXNCONSO, RXNSAT, and RXNSTY, respectively. The OCD files only include drug names that originally were provided by sources (i.e., not SAB=RXNORM). In processing obsolete data, NLM changes the SAB to RXNORM, because they are no longer in the source data.

Metadata - RXNSAB.RRF, RXNDOC.RRF

RXNSAB and RXNDOC contain data about the RxNorm data, such as a list of term types, source provider contact information, and explanations of data types.

RXNSAB includes one row for each source in RxNorm, including SAB=RXNORM. RXNSAB contains contact information for source providers, available term types and attributes, and other information related to each RxNorm source.

Sample data from RXNSAB:

| C3265859 | C1140284 | RXNORM_12AA_121001F | RXNORM | RxNorm Vocabulary | RXNORM | 12AA_121001F | | | 2012AA | | Stuart Nelson, M.D. ; Head, MeSH Section;National Library of Medicine;8600 Rockville Pike;; Bethesda;Maryland;United States;20894;;;nelson@nlm.nih.gov; | Stuart Nelson, M.D.;He ad, MeSH Section;National Library of Medicine;8600 Rockville Pike;;Bethesda;Maryland;United States;20894;;; nelson@nlm.nih.gov; | 0 | NULL | NULL | | IN,OCD,DF,GPCK, SCD,MIN,SCDF,SBDF,DFG, TMSY,BN,PIN,ET,BPCK,SCDG,SBDC,SBD,SBDG,SY,SCDC | ORIG_SOURCE,ORIG_AMBIGUITY_FLAG, RXN_IN_EXPRESSED_FLAG,RXN_STREN GTH,RXN_QUANTITY, RXTERM_FORM,RXN_OBSOLETED, RXN_VET_DRUG, RXN_BN_CARDINALITY,ORIG_CODE,AMBIGUITY_FLAG, RXN_HUMAN_DRUG,UNII_CODE,ORIG_VSAB, RXN_ACTIVATED, RXN_AVAILABLE_STRENGTH,ORIG_TTY,NDC | ENG | UTF-8 | Y | Y | RxNorm work done by the National Library of Medicine | ;;;;RxNorm;;;META2012AA Full Upd ate 2012_10_01;Bethesda, MD;National Library of Medicine;;;;;;;; |

RXNDOC is actually a file borrowed from the UMLS (called MRDOC.RRF in the Metathesaurus). This file provides a brief explanation of the values for the data elements and attributes in RxNorm and the UMLS.

Sample data from RXNDOC:

ATN|NDC|expanded_form|National Drug Code corresponding to a clinical drug (e.g. 000023082503)|
LAT|ENG|expanded_form|English|
RELA|has_precise_ingredient|rela_inverse|precise_ingredient_of|
TTY|MIN|expanded_form|name for a multi-ingredient|
TTY|SCD|expanded_form|Semantic Clinical Drug|

What is the Current Prescribable Content Subset?

The Current Prescribable Content is a subset of currently prescribable drugs found in RxNorm. NLM intends it to be an approximation of the prescription drugs currently marketed in the US. The subset also includes some frequently-prescribed over-the-counter drugs.

The subset includes only the active RxNorm normalized names, codes (RxCUIs), attributes, and relationships, as well as the FDA structured product label drugs and ingredients. It does not include data from any of the other 10 RxNorm data providers, such as First DataBank, Micromedex, or the Veterans Administration. We also removed suppressed and obsolete data.

The subset uses the same pipe-delimited file format as the regular RxNorm data files. However, the subset only includes the RXNCONSO.RRF, RXNREL.RRF, and RXNSAT.RRF files.

How do I get the RxNorm data?

Conditions of use

You must have a UMLS Terminology Services (UTS) account to access the RxNorm release files. NLM does not charge for licensing RxNorm; however, the use of some non-SAB=RXNORM data may require additional licensing from those source providers. Read the UMLS Metathesaurus License Agreement for more information. Visit the UTS to sign up for an account.

RxNorm Release files

You can download RxNorm as a zip file from the RxNorm Files page. The zip file contains the RxNorm RRF data files, a README file, and MySQL and Oracle database load scripts. The zip file also includes the Current Prescribable Content subset.

RxNorm Current Prescribable Content subset

You can download a subset of currently prescribable drugs found in RxNorm from the RxNorm Files page. The subset only includes SAB=RXNORM and SAB=MTHSPL data. You do not need a license to download this subset.

RxNorm API

The RxNorm API is allows access to RxNorm data via SOAP/WSDL. Visit the RxNorm API page for more information.

RxNav

RxNav is an application built upon the RxNorm API. RxNav provides searching and browsing capabilities of the RxNorm data. You do not need a license to view SAB=RXNORM data in RxNav. Visit the RxNav page for more information.

UMLS

RxNorm is also available as a source in the UMLS Metathesaurus. Visit the UMLS Source Release Documentation page for more information on RxNorm in the UMLS. The version in the UMLS has often been superseded by a more current RxNorm release. Thus, the UMLS version of RxNorm is useful for general interoperability purposes but not as a source for the most current information.

  • Downloads - The UMLS is available for download from the UTS.
  • Browser - The Metathesaurus Browser, available via the UTS, provides searching and browsing capabilities of the UMLS data online.

How often is RxNorm released?

Full Monthly Releases

The full RxNorm data set is released on the first Monday of each month. During months when the first Monday is a Federal holiday, RxNorm is released on the following Tuesday. The monthly release schedule for 2014 is:

DateDay
January 6 Monday
February 3 Monday
March 3 Monday
April 7 Monday
May 5 Monday
June 2 Monday
July 7 Monday
August 4 Monday
September 2 Tuesday
October 6 Monday
November 3 Monday
December 1 Monday

Weekly Updates

RxNorm is updated every Wednesday with newly-approved drug information from the MTHSPL source vocabulary. Weekly updates are meant to be used in conjunction with the most recent full monthly release and any previous weekly updates for that same month.

UMLS Semiannual Releases

RxNorm is available through the UMLS, which is updated in May and November each year. The RxNorm data in the UMLS is always a few months behind the current RxNorm monthly release. For example, the November release of the UMLS would contain the September RxNorm data. At each UMLS release, the monthly RxNorm data is synchronized with the data contained in that UMLS release.

Where can I get more information about RxNorm?

Technical documentation

For more-detailed, technical information about RxNorm, including scripts for loading RxNorm data into Oracle and MySQL databases, read the RxNorm technical documentation.

Release notes

For each monthly release, the release notes provide information about source vocabulary updates, data changes, and data counts. The RxNorm Files page contains a link to the current release notes.

Listserv

RXNORM-ANNOUNCES-L is an announcement-only listserv for information related to the RxNorm release files, technical issues related to accessing the files, and other important announcements. Visit the RXNORM-ANNOUNCES-L page to subscribe and access the list archives.

E-mail

We welcome any questions and comments at: rxnorminfo@nlm.nih.gov