Prescribable RxNorm API


Information returned
Concepts with a specified name
Service domain
HTTP request
GET  /REST/Prescribe/rxcui.xml?name=yourName&allsrc=0or1&srclist=yourSources&search=0or1or2


Searches for a name (from any vocabulary in RxNorm) and returns RxCUIs associated with the name.

The name parameter must completely match a string from an RxNorm vocabulary. To search by words or phrases (as opposed to a full name), see getApproximateMatch.

The scope of the search is either Active concepts (allsrc=0) or Current concepts (allsrc=1). When the scope is Active concepts, only concepts that have at least one active atom from the RxNorm vocabulary are returned. When the scope is Current concepts, only concepts that have at least one atom from a source in the srclist parameter are returned.

The name may match any non-suppressed atom from any source in the concept.

The precision of the search is adjustable with the search parameter. An exact search ignores only upper/lowercase. A normalized search is less strict. A combination search tries an exact search, then a normalized search if nothing was found.

Normalized matching broadens the recall of the exact match by eliminating sources of discrepancies that are usually not meaningful in drug names:

  • Word order

  • Case sensitivity

  • Punctuation

  • Suffixes that might be English inflections

  • Abbreviations, e.g., "hctz" is expanded to "hydrochlorothiazide"

  • Salts forms, e.g. "morphine sulfate" becomes "morphine"


Selectable (see parameters):

  • Active: concepts in the current RxNorm data set that have an atom with SAB=RXNORM and SUPPRESS=N

  • Current: concepts in the current RxNorm data set that have an atom with SUPPRESS=N



Notation for results

One of:
Get results in XML
Get results in JSON
nameQueryRequiredName of concept to find
allsrcQueryOptionalScope of search
One of:
Active concepts
Current concepts
srclistQueryOptionalFilter: find only concepts that include an atom from among these sources (if allsrc=1)

(Space-separated list. See getSourceTypes for the menu.)

One of:
Exact match only
Normalized match
Exact or Normalized

All query parameters are case-insensitive.

Note that HTTP requires that query parameters be "URL encoded". For instance, a "space-separated list" will, in practice, usually appear to use either a plus sign (+) or %20 as the separator. For full information on URL encoding, please refer to IETF RFC 3986, "Uniform Resource Identifier".

Output structure

Results are available as either XML or JSON.

  • The XML result has the root element rxnormdata. It is described in the XML Schema for the Prescribable RxNorm API; the relevant element structure is summarized below. Elements that would be empty might be left out.

  • The JSON result is an object {...}, analogous to the content of the XML rxnormdata. Fields that might occur multiple times in the XML are expressed as an array. Fields that would be empty might be null or left out. Numbers are expressed as strings.

Both XML and JSON results follow the same outline:

Root element in XML, or anonymous object in JSON
rxnormId (array)
A concept associated with the requested ID

Example: Find drug by name

XML: https://rxnav.nlm.nih.gov/REST/Prescribe/rxcui?name=lipitor

JSON: https://rxnav.nlm.nih.gov/REST/Prescribe/rxcui.json?name=lipitor

An XML result is shown below.