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 in two different ways: 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.

SOAP Function REST Resource Description
findClassById /class/byId SOAP FUNCTION TO BE DEPRECATED. Use findClassesById instead
findClassesById /class/byId newFind the drug classes from a class identifier
findClassByName /class/byName Find drug classes from a class name
findSimilarClassesByClass /similar Find similar class membership
findSimilarClassesByDrugList /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
getClassGraph /classGraph SOAP FUNCTION TO BE DEPRECATED. Use getClassGraphBySource instead
getClassGraphBySource /classGraph newGet 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 /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