OpenFDA fields

Different datasets use different drug identifiers—brand name, generic name, NDA, NDC, etc. It can be difficult to find the same drug in different datasets. And some identifiers, like pharmacologic class, are useful search filters but not available in all datasets.

OpenFDA features harmonization on drug identifiers, to make it easier to both search for and understand the drug products returned by API queries. These additional fields are attached to records in all categories, if applicable.

When you query an endpoint, you can search by:

  • Fields native to records served by that endpoint.

  • Harmonized openFDA fields, if they exist.

OpenFDA does not rewrite original records. These additional fields are annotations, in special openfda dictionary of values.

Harmonization Chart

The below chart provides the specific fields which are harmonized in each category. Note that not all datasets utilize harmonization.

Limits of openFDA harmonization

Not all records have harmonized fields. Because the harmonization process requires an exact match, some drug products cannot be harmonized in this fashion—for instance, if the drug name is misspelled. Some drug products will have openfda sections, while others will never, if there was no match during the harmonization process. Conversely, searching in these fields will only return a subset of records from a given endpoint.