Nlm Nih Gov RxNorm API
✓ Official Vendor SpecHealthcarePharmacynone34 EndpointsREST
For Agents
Resolve and normalize US prescription drug names, NDCs, and brand-generic relationships using RxNorm RxCUI identifiers and crosswalks to source vocabularies.
Use for: I need to normalize a free-text drug name to an RxCUI, Find all brand name equivalents for a generic medication, Look up the active ingredients in a clinical drug concept, Check whether a National Drug Code maps to a current RxCUI
Not supported: Does not handle drug interactions, dosing recommendations, adverse event reports, or pricing — use for RxNorm drug name normalization and NDC crosswalks only.
The RxNorm API exposes the National Library of Medicine's normalized drug nomenclature, mapping brand names, generic names, NDCs, and clinical drug concepts to stable RxCUI identifiers. Agents can resolve drug name variants, traverse relationships between ingredients and clinical drug forms, retrieve historical NDC status, and check approximate term matches for misspellings. The dataset spans the full US prescription drug ecosystem with monthly updates from FDA and other source vocabularies. Suitable for medication reconciliation, e-prescribing validation, and clinical decision support pipelines.
Install Jentic One Beta
Connect the RxNorm API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the RxNorm API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with RxNorm API.
Convert a free-text drug name into a normalized RxCUI identifier via /approximateTerm and /rxcui
Retrieve all related concepts for a drug, including ingredients, clinical drug components, and dose forms
Look up the active status, generic equivalent, and brand variants attached to a given RxCUI
Map National Drug Codes to RxCUIs and walk historical NDC status changes for a clinical drug
Fetch term type taxonomies, source vocabularies, and property categories used across RxNorm
Suggest spelling corrections for malformed drug name input via /spellingsuggestions
Use Cases
Patterns agents use RxNorm API for, with concrete tasks.
★ Medication Reconciliation
Normalize free-text medication entries from patient intake forms or claims data into RxCUI identifiers so duplicate orders, dose mismatches, and brand-generic substitutions can be detected reliably. The RxNorm API resolves variant spellings via /approximateTerm and links each result to ingredients, strengths, and dose forms. This eliminates string-match heuristics in EHR integration pipelines and produces an auditable mapping between source documents and a stable code system.
Take the string 'Lipitor 20mg tablet', call /approximateTerm to get candidate RxCUIs, then call /rxcui/{rxcui}/related to retrieve the generic ingredient atorvastatin
NDC to RxNorm Crosswalk
Pharmacy claims and inventory systems track drugs by National Drug Code, but clinical decision support and analytics require RxCUIs. The /ndcstatus and /rxcui/{rxcui}/ndcs endpoints expose the bidirectional crosswalk and historical status changes, so a pipeline can reconcile a billing-side NDC against the current normalized clinical drug concept. Mapping coverage spans active, alien, obsolete, and unreleased NDC states.
Submit an 11-digit NDC like 00071015523 to /ndcstatus and resolve the returned RxCUI to its clinical drug name via /rxcui/{rxcui}/properties
Brand-Generic Substitution Lookup
Formulary and prior authorization workflows often need to surface generic alternatives for a branded prescription. The /rxcui/{rxcui}/generic and /rxcui/{rxcui}/related endpoints return generic equivalents and related ingredient concepts so substitution rules can be evaluated without scraping FDA Orange Book data. Each result includes term type so callers can filter to the appropriate concept granularity.
Call /rxcui/{rxcui}/generic with the RxCUI for a branded drug and return the generic ingredient name and strength
AI Agent Clinical Lookup
Healthcare-focused AI agents need a structured drug knowledge base to answer prescribing questions, validate medication lists, and link to interaction services. Through Jentic, an agent searches for 'normalize a drug name to rxcui', loads the RxNorm operation schema, and executes the call without managing the public RxNav endpoint directly. Because the API is public and unauthenticated, Jentic still tracks usage, retries, and response shape.
Use Jentic search to find the RxNorm normalize-drug-name operation, load its schema, and execute it for the input 'metformin 500'
Key Endpoints
34 endpoints — the rxnorm api exposes the national library of medicine's normalized drug nomenclature, mapping brand names, generic names, ndcs, and clinical drug concepts to stable rxcui identifiers.
METHOD
PATH
DESCRIPTION
GET
/approximateTerm
Find RxNorm concepts matching a free-text drug name
GET
/rxcui
Resolve a drug name to one or more RxCUIs
GET
/rxcui/{rxcui}/related
Retrieve concepts related to a given RxCUI by term type
GET
/rxcui/{rxcui}/generic
Get the generic equivalent of a branded RxCUI
GET
/rxcui/{rxcui}/ndcs
List NDCs currently mapped to an RxCUI
GET
/ndcstatus
Check the status and RxCUI mapping for a National Drug Code
GET
/spellingsuggestions
Suggest spelling corrections for malformed drug names
GET
/approximateTerm
Find RxNorm concepts matching a free-text drug name
GET
/rxcui
Resolve a drug name to one or more RxCUIs
GET
/rxcui/{rxcui}/related
Retrieve concepts related to a given RxCUI by term type
GET
/rxcui/{rxcui}/generic
Get the generic equivalent of a branded RxCUI
GET
/rxcui/{rxcui}/ndcs
List NDCs currently mapped to an RxCUI
GET
/ndcstatus
Check the status and RxCUI mapping for a National Drug Code
GET
/spellingsuggestions
Suggest spelling corrections for malformed drug names
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
RxNorm is anonymous, so no credential is provisioned. Jentic still proxies the call so that audit logs, retry policy, and response normalization are consistent with authenticated APIs in the same agent toolchain.
Intent-based discovery
Agents search by intent (e.g. 'normalize a drug name to rxcui') and Jentic returns the matching RxNorm operation with its input schema, eliminating manual browsing of the RxNav documentation.
Time to first call
Direct integration: 1-2 days reading the RxNav docs and writing path-specific clients for /approximateTerm, /rxcui, and /ndcstatus. Through Jentic: under 30 minutes — search, load, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using RxNorm API through Jentic.
What authentication does the RxNorm API use?
The RxNorm REST API at rxnav.nlm.nih.gov/REST is fully public and requires no API key, OAuth token, or registration. Through Jentic the call still passes through the credential broker, but no secret is provisioned because the upstream service is anonymous. Jentic manages rate limits and retries on the agent's behalf.
Can I find the generic equivalent of a brand-name drug with the RxNorm API?
Yes. Resolve the brand name to an RxCUI via /approximateTerm or /rxcui, then call /rxcui/{rxcui}/generic to retrieve the generic concept, or /rxcui/{rxcui}/related with the appropriate term type filter to get ingredients and clinical drug forms.
What are the rate limits for the RxNorm API?
NLM enforces a soft limit of roughly 20 requests per second per IP for RxNav services. There is no daily cap, but bulk lookups should be batched and cached. Jentic handles backoff automatically when the service returns throttling responses.
How do I normalize a drug name with the RxNorm API through Jentic?
Run pip install jentic, then ask Jentic to search for 'normalize a drug name to rxcui'. Jentic returns the /approximateTerm operation schema; load it, pass the drug string as the term parameter, and execute. The response contains ranked RxCUI candidates with scores.
Is the RxNorm API free to use?
Yes. RxNorm is produced and hosted by the US National Library of Medicine and is free for all uses, including commercial. Attribution to NLM is requested when redistributing the data.
Can the RxNorm API tell me which NDCs map to a current RxCUI?
Yes. Call /rxcui/{rxcui}/ndcs for the current set or /rxcui/{rxcui}/allhistoricalndcs for the full status history. Each entry includes the NDC, status (active, obsolete, alien), and the dates the mapping was valid.
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