getRxcuiHistoryStatus enhancement - March 2023

The RxNorm API's getRxcuiHistoryStatus function has been enhanced to reflect ongoing curation of the RxNorm vocabulary, support historical clinical analytics, and improve consistency of reports about concepts that were active at different times.

Summary of principal changes:

  • Obsolete concepts are described by their relations and attributes in the current RxNorm release, instead of the RxNorm release in which the obsolete concept was last active.
  • Remapped concepts are described by a name in the current RxNorm release (an entry in RXNCONSO or, if none, then RXNATOMARCHIVE) and a list of active and obsolete replacement concepts. No longer returned are the outdated former attributes of the discontinued RxCUI.
  • NotCurrent concepts are described by a source vocabulary, name, and TTY that are currently in RxNorm, if any.

Detailed notes follow.

Current data

Affected concepts getRxcuiHistoryStatus changes
Remapped RxCUIs Remapped RxNorm RxCUIs are reported without the no-longer-curated properties of the formerly associated concept.You may use the remappedRxcui(s) to retrieve the properties of an equivalent, currently maintained concept.
Example: Remapped RxCUI 541862 is (still) reported with its replacement in the “remappedRxCui” element. Please query the replacement concept, 207346, to find information about the drug.

Replacement concepts may be obsolete. A new response element, “remappedActive”, has been added to indicate with YES or NO whether each replacement concept is active.
For example, 1000022 has status “Remapped” and one remappedRxCui, 1048306, which is obsolete. Previously, only active replacements were reported.

Concepts that merged with obsolete replacement concepts (and no active concepts) are categorized as Remapped. Previously, they were categorized as NotCurrent. As a result, about 27,000 RxCUIs have changed from NotCurrent to Remapped.
Obsolete RxNorm concepts Names, attributes, and relations are reported from the current RxNorm. They reflect curation that continues even after a concept becomes obsolete. Changes include normalized names, BoSS and related attributes, dose form groups, and whether a concept is within the scope of the SAB=RXNORM vocabulary. This change affects 53% of obsolete concepts.
Example: in obsolete pack 1005905, ingredient 114202 changed name from “Lactate” to “lactate”, active ingredient and moiety were added, and the basis-of-strength substance changed from “ammonium lactate” to “lactic acid”.
NotCurrent RxCUIs that had an RxNorm term at one time Concepts that were removed from the RxNorm vocabulary are no longer reported with the properties that RxNorm expunged. Example: 317571.
NotCurrent concepts from other vocabularies Concepts that were never included in the RxNorm vocabulary, or were included only as OBD or OCD terms, or lost their RxNorm vocabulary term without being merged into another concept, are identified by a name provided by a current RxNorm source vocabulary if there is one, and no name otherwise.
Example 1: RxCUI 1000, previously identified as “[CN850] ANTIPYRETICS” from NDFRT, is now identified as “ANTIPYRETICS” from VANDF because RxNorm no longer includes the NDFRT vocabulary. (There are about 11,500 such cases.)
Example 2: RxCUI 205823, previously identified as “Ampicillin 10000 MG Injectable Solution [Omnipen-N]” from RXNORM, was in a concept that currently has only a term from another vocabulary. (There are about 4000 such cases.)

Definitional features

Affected concepts getRxcuiHistoryStatus changes
Obsolete and “Quantified” concepts Definitional features, from the current release of RxNorm, have been added to the reports for Obsolete and “Quantified” concepts. This change affects 37% of obsolete concepts and 35% of concepts of status “Quantified”.
Example 1: Obsolete SBD 1006416 was reported without dose form groups, but now has them.
Example 2: “Quantified” SCD 2475341 was reported without ingredients, dose forms, or dose form groups, but now has them.
SCDC and SBDC concepts A basis-of-strength substance (BoSS) is no longer reported for SCDC and SBDC terms, because RxNorm moved BoSS accounting to the drug concept.
SCDF and SBDF concepts SCDF and SBDF concepts defined by a dose form via an obsolete SCD or SBD are reported with their definitional dose form. Example: Active SCDF 1009218 was missing its dose form, but now has it.
Concepts of certain types not defined by a dose form (concepts of type BN, IN, MIN, PIN, SCDC, SCDG, SBDC, SBDG) Dose forms are no longer reported as a “definitional feature” for TTYs not defined by a dose form, such as SCDC and IN. Example: 83367, an ingredient.

Quantified forms

Affected concepts getRxcuiHistoryStatus changes
Active and Obsolete unquantified concepts Quantified forms are reported wherever RxNorm provides a has_quantified_form relationship (not only for concepts of status “Quantified”). This change affects less than 1% of active and obsolete concepts.
Example: Active SCD 897640 “verapamil hydrochloride 180 MG Extended Release Oral Tablet”, was reported without a quantifiedRxcui, and now reports one quantified form, 897635 “24 HR verapamil hydrochloride 180 MG Extended Release Oral Tablet”.
Obsolete quantified forms Reports including quantified forms list not only Active, but also Obsolete quantified forms.
Example: Obsolete SBD 844410 “nifedipine 20 MG Extended Release Oral Tablet [Cardilate MR]” has obsolete quantified form SBD 103944 “12 HR nifedipine 20 MG Extended Release Oral Tablet [Cardilate MR]”

Dates of activity

Affected concepts getRxcuiHistoryStatus changes
Concepts active before May 2006 Concepts are reported as “active” as far back as April 2005. Previously, the earliest activeStartDate was May 2006. This change affects 23% of active and 47% of obsolete concepts. Example: 83367
Concepts active for non-contiguous periods of time activeStartDate reflects the first period of activity for concepts that have been active in non-contiguous monthly releases. This change affects 1% of concepts in the RxNorm vocabulary.
Example: Active SBD 539815, currently known as “solifenacin succinate 10 MG Oral Tablet [Vesicare]”, was active from September 2005 through January 2006 and again from January 2009 to present.