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Unified Medical Language System® (UMLS®)

RxNorm Release Notes

September Release - 09/07/2021

For additional information about RxNorm releases, including scripts for loading the RxNorm data into Oracle and MySQL databases, read the RxNorm Technical Documentation.


The following sources with version names in bold have been updated since the previous RxNorm release:

Source NameSABVersion
Vaccines Administered CVX CVX_2021_08_25
DrugBank DRUGBANK DRUGBANK5.0_2021_08_03
Gold Standard Drug Database GS GS_2021_08_06
Multum MediSource Lexicon MMSL MMSL_2021_08_01
Micromedex RED BOOK MMX MMX_2021_08_02
FDA Structured Product Labels MTHSPL MTHSPL_2021_08_27
FDB MedKnowledge (formerly NDDF Plus) NDDF NDDF_2021_08_11
RxNorm normalized names and codes RXNORM RXNORM_20AA_210907F
US Edition of SNOMED CT (drug information) SNOMEDCT_US SNOMEDCT_US_2021_07_31
USP Compendial Nomenclature USP USP_2021_07_15
Veterans Health Administration National Drug File VANDF VANDF_2021_07_30

The following sources have not been updated since the previous RxNorm release:

Source NameSABVersion
Anatomical Therapeutic Chemical Classification System ATC ATC_2021
Medical Subject Headings (MeSH) MSH MSH2021_2021_01_25
CMS Formulary Reference File MTHCMSFRF MTHCMSFRF_2020

*Reminder: As of October 2017, Medi-Span data will not be included in the RxNorm or UMLS releases. If you have questions about Medi-Span, please contact:


BoSS Attribute Changes

Basis of Strength Substance (BoSS) attributes in RxNorm provide improved alignment with international drug data standards. To better serve users and improve computability, three RxNorm BoSS attributes changed: RXN_BOSS_AI, RXN_BOSS_AM, and RXN_BOSS_FROM. Two of the attribute names changed; the attribute values now include RXCUIs in place of text descriptions; and these attributes are now associated with SCDs/SBDs rather than SCDCs.

Summary of BoSS Attribute Changes beginning September 2021:

  • Two Attribute Names (ATN) renamed:
    • RXN_BOSS_AI renamed to RXN_AI
    • RXN_BOSS_AM renamed to RXN_AM
  • RXCUIs replaced names for two RxNorm Attribute Values (ATV), and the relevant SCDC RXCUI are included in curly brackets. The new formats are:

(NOTE: SCDC_RXCUI is the RXCUI of the SCDC that is responsible for the active ingredient/moiety value. The IN/PIN_RXCUI is the RXCUI of the active ingredient (AI) or active moiety (AM) with term type of IN or PIN. Previously, an IN/PIN string was the value.

  • Association of the attributes below moved from an SCDC to a Semantic Clinical Drug (SCD) or Semantic Branded Drug (SBD):
    • RXN_AI
    • RXN_AM

Note that the BoSS attribute changes will be implemented in a phased approach. This change impacts many concepts, including multi-ingredient products. However, several inhalation gas products and multivitamin products are not affected at this time. BoSS attributes related to units, numerators, and denominators also remain unchanged.

As an example, starting with the September release, SCD RXCUI 597987 “amlodipine 10 MG / atorvastatin 10 MG Oral Tablet” has the following attributes:

  • RXN_AI = {329526} 104416
  • RXN_AM = {329526} 17767
  • RXN_BOSS_FROM = {329526} AM
  • RXN_AI = {597970} 83366
  • RXN_AM = {597970} 83367
  • RXN_BOSS_FROM = {597970} AM

(Note: multiple sets of BoSS attributes exist because RXCUI 597987 contains multiple active ingredients)

Prior to the September release, the BoSS attributes for SCD RXCUI 597987 were associated with SCDCs and included text descriptions:

  • For the amlodipine SCDC component “amlodipine 10 MG” with RXCUI = 329526,
    • RXN_BOSS_AI = Amlodipine Besylate
    • RXN_BOSS_AM = Amlodipine
  • For the atorvastatin SCDC component “atorvastatin 10 MG” with RXCUI = 597970,
    • RXN_BOSS_AI = Atorvastatin calcium
    • RXN_BOSS_AM = atorvastatin

New Semglee (insulin glargine-yfgn) Concepts Added

As previously announced, the FDA approved the first interchangeable biosimilar insulin product Semglee. These Semglee products first became available in the RxNorm August 4, 2021 weekly releases and are included in the September 2021 monthly release also.

Please note that concepts representing the interchangeable biosimilar product include an ingredient name with a four-letter suffix and have distinct National Drug Codes (NDCs) compared to the Semglee concepts that already existed.

New Concepts for Semglee interchangeable biosimilar insulin products are:

  • RXCUI: 2563973
  • SBD: 3 ML insulin glargine-yfgn 100 UNT/ML Pen Injector [Semglee]
  • NDC: 49502025171, 49502025173, 49502025175
  • RXCUI: 2563977
  • SBD: insulin glargine-yfgn 100 UNT/ML Injectable Solution [Semglee]
  • NDC: 49502025080

Concepts for the already existing Semglee products are:

  • RXCUI: 2377231
  • SBD: 3 ML insulin glargine 100 UNT/ML Pen Injector [Semglee]
  • NDC: 49502019671, 49502019673, 49502019675
  • RXCUI: 2377134
  • SBD: insulin glargine 100 UNT/ML Injectable Solution [Semglee]
  • NDC: 49502019580

Data Counts

Term Type or AttributeNumber
Active GPCKs453
Active BPCKs532
Active SCDs17118
Active SBDs9502
Active RXNORM MINs3761
Active RXNORM INs13513
Active RXNORM PINs3137
Active RXNORM BNs5166
Active RXNORM DFs121
Obsolete GPCKs242
Obsolete BPCKs208
Obsolete SCDs18437
Obsolete SBDs10888
Obsolete RXNORM MINs0
Obsolete RXNORM INs0
Obsolete RXNORM PINs0
Obsolete RXNORM BNs6135
Obsolete RXNORM DFs63
Editor-suppressed SCDs1840
Editor-suppressed SBDs1516
Distinct SAB=RXNORM NDCs255305

Last Reviewed: September 7, 2021