Skip Navigation Bar
National Library of Medicine Technical BulletinNational Library of Medicine Technical Bulletin

Table of Contents: 2021 SEPTEMBER–OCTOBER No. 442

Previous Next

RxNorm September 2021 Monthly Release

RxNorm September 2021 Monthly Release. NLM Tech Bull. 2021 Sept-Oct;(442):b1.

2021 September 07 [posted]

The RxNorm September monthly release became available for download on Tuesday, September 7, 2021. It includes changes to several RxNorm Basis of Strength Substance (BoSS) attributes. Concepts for the first interchangeable biosimilar insulin product Semglee are also included. See below for more details. 


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
NLM Technical Bulletin National Library of Medicine National Institutes of Health