An Overview to RxNorm - http://www.nlm.nih.gov/research/umls/rxnorm/overview.html In RxNorm, the name of a clinical drug combines its ingredients, strengths, and/or form. RxCUI The concept is assigned an RxNorm concept unique identifier (RXCUI) of 575803. This RXCUI always designates the same concept, no matter the form of the name and no matter in what table it is found. Drugs whose names map to the same RXCUI are taken to be the same drug—identical as to ingredients, strengths, and dose forms. Conversely, drugs that differ in any of these Unique Identifiers and their Source Databases: