Drug Classes¶
Retrieves drug class information for a given RxNorm concept (RXCUI). It queries the RxClass service and returns the classes the drug belongs to, optionally filtered by a specific classification system. Results are returned as a formatted JSON string alongside a status message.
Usage¶
Use this node when you have an RXCUI for a drug and need to know its classifications (e.g., ATC, MED-RT, SNOMED CT). Commonly used after a step that normalizes a drug name or NDC to an RXCUI. Set the classification system to ALL to get a broad view across sources, or choose a specific system to focus the results.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| rxcui | True | STRING | The RxNorm Concept Unique Identifier for the drug to classify. Must be a non-empty string of digits. | 83367 |
| classification_system | True | ENUM | Which classification system to use for results. Use ALL to query across available systems, or select a specific source such as ATC, MEDRT, SNOMEDCT, VA, etc. | ALL |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| drug_classes | STRING | A JSON-formatted string containing the RXCUI, the classification system used, and the classes returned by the service. | { "rxcui": "83367", "classification_system": "ALL", "classes": { ... } } |
| status | STRING | Human-readable status indicating success or describing the error encountered. | Successfully retrieved drug classes for RXCUI 83367 |
Important Notes¶
- Input validity: rxcui must be non-empty; empty inputs return "{}" with an error status.
- Classification scope: Set classification_system to ALL to include all supported systems; choosing a specific system limits results.
- Output format: drug_classes is a JSON string; downstream nodes may need to parse it to access fields.
- Error propagation: If the upstream API returns an error, the node returns that error payload as JSON in drug_classes and a status starting with "API Error:".
- System options: Valid classification systems are constrained to the supported list (e.g., ALL, ATC, MEDRT, SNOMEDCT, VA, etc.). Using unsupported values will result in an API error.
Troubleshooting¶
- Empty output ("{}") and error status: Ensure rxcui is provided and not blank.
- API Error in status: Verify the classification_system is one of the supported values (e.g., ALL, ATC, MEDRT, SNOMEDCT, VA). Try switching to ALL to test connectivity.
- Unexpected structure under classes: The external service can change or vary fields; inspect the JSON to confirm the paths you parse.
- No classes returned for a valid RXCUI: The drug may not be mapped in the chosen system; try ALL or a different system.
- Intermittent failures: May indicate remote service issues or rate limiting; retry after a short delay.