RxNorm Related Concepts¶
Retrieves RxNorm concepts that are related to a given RxCUI by a specified relationship type. It queries the RxNorm service and returns a structured JSON string of related concepts along with a status message. Typical relationships include ingredient, brand/generic, and formulation linkages.
Usage¶
Use this node when you have an RxCUI (e.g., from a prior RxNorm search) and need to explore related concepts such as precise ingredients, brand names, or other clinical relationships. Common workflows include: searching for a drug to get an RxCUI, then using this node to expand to brand/generic variants or formulations for downstream analysis or display.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| rxcui | True | STRING | The RxNorm Concept Unique Identifier of the starting concept to explore relations from. | 313 |
| relationship_type | True | STRING | The RxNorm relationship type to filter related concepts by. Examples include 'has_precise_ingredient' and 'has_brand_name'. | has_precise_ingredient |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| related_concepts | STRING | A JSON-formatted string containing the related concepts returned by the RxNorm service for the given RxCUI and relationship type. | { "rxcui": "313", "relationship_type": "has_precise_ingredient", "relatedConcepts": [ { "rxcui": "12345", "name": "Example Drug", "tty": "SCD" } ] } |
| status | STRING | A human-readable message indicating success or describing any encountered error. | Successfully retrieved related concepts for RXCUI 313 |
Important Notes¶
- Relationship types: Valid values must be supported by RxNorm (e.g., 'has_precise_ingredient', 'has_brand_name'). Unsupported values will return empty or error responses.
- Input format: This node expects a single RxCUI as a string. Ensure the input is not empty and is a valid RxNorm identifier.
- Output structure: The related_concepts output is a JSON-formatted STRING; downstream nodes should parse it before further processing.
- External dependency: Results depend on the availability and response of the RxNorm REST service; transient network or service issues can affect output.
Troubleshooting¶
- Empty results: Verify the RxCUI is correct and the relationship_type is valid for that RxCUI. Try alternative relationship types such as 'has_brand_name' or 'has_precise_ingredient'.
- API error message in status: Indicates a remote service or network issue. Retry later, and ensure your environment allows outbound HTTPS requests to the RxNorm API.
- Malformed JSON downstream: Remember the first output is a STRING containing JSON; parse it before attempting to access fields.
- Unexpected relationships: Different RxCUIs support different relationship types. Confirm the concept type (ingredient, brand, clinical drug) and adjust the relationship_type accordingly.