RxClass API


Information returned
Version of a data set from which RxClass draws drug-class relations
Service domain
HTTP request
GET  /REST/rxclass/version/relaSource.xml


Get the version of a data set from which RxClass draws drug-class relations.

Relationship SourceVersion comes fromExample
ATCRXNSAB.SVER where RSAB='ATC' (less the "ATC_" prefix)2023_03_21
ATCPRODDate in YYYYMMDD form20230605
MEDRT, FDASPL, & FMTSMEMED-RT Core.xml2021.09.07
RXNORMRxNorm API getRxNormVersion04-Oct-2021
VAAcquisition date (in the format used by RxNorm release notes)2021_08_31
SNOMEDCTConcept 13887500520220301

RxClass acquires DailyMed class-member data by means of a rolling update and does not associate a version number with it.


relaSourcePathRequiredData set

(See getSourcesOfDrugClassRelations for the menu.)


Notation for results

One of:
Get results in XML
Get results in JSON

Note that HTTP requires that query parameters be "URL encoded". For full information on URL encoding, please refer to IETF RFC 3986, "Uniform Resource Identifier".

Output structure

Results are available as either XML or JSON.

  • The XML result has the root element rxclassdata. It is described in the XML Schema for the RxClass API; the relevant element structure is summarized below. Elements that would be empty might be left out.

  • The JSON result is an object {...}, analogous to the content of the XML rxclassdata. Fields that might occur multiple times in the XML are expressed as an array. Fields that would be empty might be null or left out. Numbers are expressed as strings.

Both XML and JSON results follow the same outline:

Root element in XML, or anonymous object in JSON
Version of the data set that declares the drug-class relations

Example: SNOMED CT version used in RxClass

XML: https://rxnav.nlm.nih.gov/REST/rxclass/version/SNOMEDCT

JSON: https://rxnav.nlm.nih.gov/REST/rxclass/version/SNOMEDCT.json

An XML result is shown below.