/v1/interchangeability/alternativesA product code returns the product’s FDA rating and the marketed products FDA rates interchangeable with it, one per product NDC. The product’s own application decides the book: a BLA reads the Purple Book, an NDA or ANDA the Orange Book. A page can be short, even empty, while next_cursor is set; keep paging. A subject no book rates answers 200 with an empty list, which does not mean none exist.
AuthorizationstringRequiredBearer token with your API key. Keep the key server-side.
Idempotency-KeystringOptionalMakes a retry count once. 8 to 128 letters, digits and . _ : / + -, starting with a letter or digit. For 24 hours the key is bound to your workspace and the exact request; reusing it for different work is refused with 409.
Values go in the query string; repeat a field to send several values.
codestringRequiredat most 512 charactersA code for one product: a product or package NDC, a GTIN or GS1 scanner text. A label set ID, application number or RxCUI that carries exactly one product is accepted. A code that names several products, or a Drug, answers 409 with candidates to choose from. A retired RxCUI is 410, an RxCUI RxNorm’s history does not cover is 404, and one that is not a drug is 422.
include_not_interchangeablebooleanOptionalDefaults to falseAlso list products under the same FDA heading or reference product that FDA does not rate interchangeable, flagged by interchangeable and outcome.
limitintegerOptionalDefaults to 20min 1 · max 100Alternatives per page, at most 100.
cursorstringOptionalThe cursor from the previous page of this same listing.
One object. Optional fields are left out when empty; a few return null for unknown, as their sentences say. Dates are YYYY-MM-DD and times ISO 8601 UTC.
subjectRatedProductRequiredThe product you asked about, with its FDA rating.
alternativesarray of AlternativeRequiredThe products FDA rates interchangeable with it, each with its rating and outcome.
Errors and limits lists every code and the limits behind them.