Intera
Replacement for the discontinued NLM drug interaction API
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What is Intera?
RxCheck is a developer-grade Drug-Drug Interaction (DDI) Checker API built as a direct replacement for the discontinued NLM DDI endpoint. The tool provides programmatic access to 500K+ drug-drug interaction pairs sourced from DDInter 2.0, openFDA, and the ONC High Priority list. It returns structured JSON responses containing severity levels (minor, moderate, major), interaction mechanisms, and management recommendations in a single API call.
Key features include RxNorm support where brand names, generic names, and RxCUI identifiers all resolve correctly, cached response times under 50ms for fast performance, and a free tier available without requiring a credit card. The API supports both individual drug pair checks via GET requests and batch/polypharmacy checking via POST /v1/interactions/batch endpoint for full medication lists. The response includes metadata like queries remaining and cache hit status.
This tool is designed for developers building healthcare applications, Electronic Health Record (EHR) systems, pharmacy software, telemedicine platforms, and clinical decision support tools. It serves companies and developers who need reliable drug interaction data programmatically for patient safety checks, medication management apps, or clinical workflow integration.
The API endpoint is https://api.rxcheck.dev/v1/interactions and uses X-API-Key header authentication with keys prefixed rxck_live_ for live keys. The structured output includes fields like interaction.found, interaction.severity, interaction.onc_high_priority, interaction.mechanism, interaction.evidence_level, and sources array indicating which database the interaction was found in.
Intera pricing
Pricing model: Freemium
Free tier available with no credit card required. The homepage states Free tier available — no credit card required but does not publish specific query limits or paid plan pricing details on the main page. API keys use the prefix rxck_live_ for live production keys. Queries remaining is returned in metadata to track quota usage.
Intera pros
- Free tier available with no credit card required
- 500K+ drug-drug interaction pairs in database
- Direct replacement for discontinued NLM DDI endpoint
- Sources from DDInter 2.0, openFDA, and ONC High Priority list
- RxNorm support resolves brand names, generics, and RxCUI correctly
- Cached response time under 50ms
- Structured JSON with severity, mechanism, and management data
- ONC high priority flag included in response
- Evidence level included for clinical confidence
- Sources array shows which database found the interaction
- Batch endpoint for polypharmacy full medication list checking
- Simple single API call for full interaction data
- Metadata includes queries remaining for quota tracking
- Cache hit indicator for performance optimization
- Developer-grade API designed for production integration
Intera cons
- No food-drug or drug-alcohol interaction checking mentioned
- No drug-condition contraindication checking
- API key required even for free tier usage
- Limited documentation visible on main page
- No explicit rate limit numbers published on homepage
- No mentioned SDKs or client libraries
- Batch endpoint requires POST not GET
- No free trial without API key mentioned
Frequently asked questions about Intera
What is RxCheck and what does it do?
RxCheck is a developer-grade Drug-Drug Interaction (DDI) Checker API that returns structured JSON with severity, mechanism, and management data for drug pairs. It provides access to 500K+ interaction pairs from DDInter 2.0, openFDA, and the ONC High Priority list through a single API call.
Why was RxCheck built?
RxCheck was built as a direct replacement for the discontinued NLM DDI endpoint, providing developers with a reliable alternative for drug interaction checking in their applications.
What data sources does RxCheck use?
RxCheck sources interaction data from three main databases: DDInter 2.0, openFDA, and the ONC High Priority list, providing comprehensive coverage of drug-drug interactions.
How fast is the API response time?
The cached response time is under 50ms, making it suitable for real-time clinical decision support and patient-facing applications where speed matters.
Does RxCheck support RxNorm identifiers?
Yes, RxCheck fully supports RxNorm where brand names, generic names, and RxCUI identifiers all resolve correctly, making integration with existing healthcare systems easier.
What fields are included in the API response?
The response includes interaction.found (boolean), interaction.severity (minor/moderate/major), interaction.onc_high_priority (boolean), interaction.mechanism (text), interaction.evidence_level (letter grade), sources (array), and meta.queries_remaining and meta.cache_hit.
Is there a free tier available?
Yes, RxCheck offers a free tier that requires no credit card, making it accessible for developers to test and build applications without upfront commitment.
Can I check multiple drugs at once?
Yes, for polypharmacy checking of full medication lists, RxCheck provides a batch endpoint at POST https://api.rxcheck.dev/v1/interactions/batch for checking multiple drugs simultaneously.
How do I authenticate with the API?
Authentication uses the X-API-Key header with your API key. Production keys use the prefix rxck_live_ followed by a random string, similar to other REST API key formats.
Who is RxCheck designed for?
RxCheck is designed for developers building healthcare applications including EHR systems, pharmacy software, telemedicine platforms, clinical decision support tools, medication management apps, and any application needing programmatic drug interaction checking for patient safety.