How It Works

Rx Builder uses a local-first architecture with smart caching. Drug data is loaded once and stored in your browser's IndexedDB for instant offline access on subsequent visits.

• FHIR Server (Online): Connects to a FHIR terminology server to fetch the latest FDA drug data using FHIR standard APIs. Data is cached locally for offline use.
• CSV File (Offline): Load a local CSV file from the FDA Philippines Verification Portal. The data is cached and available offline immediately.

Once loaded, all searches happen instantly in your browser using a pre-built search index. Build prescriptions, add custom medications, and print or save as PDF.

Architecture & Caching

The app is built as a single-page progressive web app (PWA) with zero server-side dependencies:

• IndexedDB Storage: Drug data (~34,000 records) is cached in your browser using IndexedDB, allowing instant startup even when offline
• Smart Cache Updates: When online, the app automatically checks for new data in the background and updates silently
• Fallback Strategy: If FHIR server is unavailable, automatically uses cached data or falls back to CSV
• LocalStorage: Prescription drafts are saved to browser local storage
• Service Worker: Enables PWA installation and offline functionality

FHIR Terminology Server

This app queries drug data using the FHIR (Fast Healthcare Interoperability Resources) standard. It fetches concepts from a CodeSystem resource which contains all drug properties (generic name, brand name, strength, form, classification, manufacturer, etc.) and validates codes against a ValueSet for the complete FDA Philippines drug database.

The terminology server is powered by Ontoserver on FHIRLab by the SSCP project (Strengthening Standards Capability Project), a capacity development program for Digital Health Standards and Interoperability in the Southeast Asia and Pacific Region.

How to Use

1. Click "Load from FHIR Server" for online data, or load a local CSV file
2. Search for drugs using the search tab
3. Build prescriptions in the Rx tab
4. Print or save as PDF when done

Privacy

All processing happens locally in your browser. No prescription data or personal information is ever uploaded to any server. Your data is stored in:

• IndexedDB: Drug database cache (public FDA data)
• LocalStorage: Your prescription drafts only

Tips

• Use cross-field search: type "Amlo Exfo" to find Amlodipine (generic) + Exforge (brand)
• Save drafts locally before printing
• Works completely offline after first data load
• Install as a PWA on mobile for quick access