# The Drug-Drug Interaction API stops working

Calls to /REST/interaction/* on RxNav APIs stopped working on January 2, 2024.

On January 2, 2024, the Drug-Drug Interaction API was discontinued. This change affects all requests sent to /REST/interaction/* endpoints. Following that date, these calls fail.

## What to use instead

NLM offers no replacement in RxNav. You must choose and license a separate drug knowledge source to move drug-drug interaction checks to.

NLM provides no replacement: a drug-interaction data source must be chosen and licensed.

- API: RxNav APIs (rxnav.nlm.nih.gov)
- Kind: Endpoint removal
- Announced: July 3, 2023
- Takes effect: January 2, 2024
- Calls after that day: fail
- Calls it hits: `/REST/interaction/*`
- Source: [Announcement](https://lhncbc.nlm.nih.gov/RxNav/)
- Verified: October 26, 2026, against RxNav APIs's own pages
- Page: https://www.okapi.bot/providers/rxnav-apis/breaking-changes/the-drug-drug-interaction-api-stops-working/

## RxNav APIs's words

> The Drug-Drug Interaction API will be discontinued on or about January 2, 2024.

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent