RxNorm was created because a universal standard was desperately needed for drug terminologies. As a result, the FDA, the US National Library of Medicine (NLM), the Veterans Administration (VA), and the pharmacy knowledge base vendors joined forces to create RxNorm. The NLM offers the public access to the 14, 000 drugs within RxNorm via the United Medical Language System (UMLS). It supports the mapping between NDC codes, the VA's National Drug File (VANDF) and several patented drug terminologies (Hammond et al., 2014).
NLM receives drug names from 14 data sources such as Anatomical Therapeutic Chemical Classification System (ATC), Gold Standard Drug Database (GS), Medi-Span Master Drug Data Base (MDDB), Medical Subject Headings (MSH) etc. (NIH.gov,
NLM receives drug names from 14 data sources such as Anatomical Therapeutic Chemical Classification System (ATC), Gold Standard Drug Database (GS), Medi-Span Master Drug Data Base (MDDB), Medical Subject Headings (MSH) etc. (NIH.gov,