Drug Name Resolution

Accepted Input Formats

Resolution Strategy

Resolution uses a tiered approach, trying the most precise match first and falling back to progressively fuzzier methods:

1. Exact match — RxNorm findRxcuiByString with normalized matching. Handles standard drug names and brand names.
2. Fuzzy match — RxNorm getApproximateMatch for misspellings, abbreviations, and partial names. Returns ranked candidates.
3. NDC lookup — If the input matches NDC format, resolve via NDC-to-RxCUI mapping.
4. Label fallback — Query openFDA directly by generic name or brand name if RxNorm resolution fails.

Resolution Response

Every API response includes a resolutions array showing how each input drug was resolved:

{
  "resolutions": [
    {
      "inputName": "Coumadin",
      "rxcui": "11289",
      "genericName": "warfarin",
      "brandNames": ["COUMADIN", "JANTOVEN"],
      "splSetId": "abc-123-def-456",
      "labelUrl": "https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=abc-123-def-456",
      "resolved": true
    },
    {
      "inputName": "tylenl",
      "rxcui": "161",
      "genericName": "acetaminophen",
      "brandNames": ["TYLENOL"],
      "splSetId": "xyz-789",
      "labelUrl": "https://dailymed.nlm.nih.gov/...",
      "resolved": true
    }
  ]
}

Unresolved Drugs

If a drug name cannot be resolved, it appears in the resolutions array with resolved: false. The API still processes interactions for all successfully resolved drugs — one unresolved input does not block the entire request.

{
  "inputName": "xyzdrugnotfound",
  "rxcui": null,
  "genericName": null,
  "resolved": false
}