RxClass API
The RxClass API is a web service for accessing drug classes and drug members for a number of different drug class types. No license is needed to use the RxClass API.

Note: Please check the Terms of Service for restrictions on using the APIs.

The API can be accessed by clients through the RxClass RESTful web services. (The SOAP web services have been deprecated as of July 2019 and were terminated in January 2020.)

Overview of RxClass.

Functions and Resources

In the table, the base URI ( https://rxnav.nlm.nih.gov/REST/rxclass ) for the REST resources has been omitted to improve readability. The functional name is used in RxMix.

Functional Name REST Resource Description
findClassesById /class/byId Find the drug classes from a class identifier
findClassByName /class/byName Find drug classes from a class name
findSimilarClassesByClass /class/similar Find similar class membership
findSimilarClassesByDrugList /class/similarByRxcuis Find similar classes from a list of RxNorm drug identifiers
getAllClasses /allClasses Get all drug classes
getClassByRxNormDrugId /class/byRxcui Get the classes of a specified drug identifier
getClassByRxNormDrugName /class/byDrugName Get the classes of a specified drug name
getClassContexts /classContext Get the class context
getClassGraphBySource /classGraph Get the class graph of ancestors
getClassMembers /classMembers Get the drug members of a specified class
getClassTree /classTree Get the descendents of a class
getClassTypes /classTypes Get the class types
getRelas /relas Get the relationships for a source of drug relations
getSimilarityInformation /class/similarInfo Get the similarity information between members of two classes
getSourcesOfDrugClassRelations /relaSources Get the sources of drug-class relations
getSpellingSuggestions /spellingsuggestions Get spelling suggestions for a drug or class name