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RxTerms is a drug interface terminology derived from RxNorm for prescription writing or medication history recording (e.g. in e-prescribing systems, PHRs). The advantages of RxTerms are:

  • Free to use.
  • Directly links to RxNorm, the U.S. drug terminology standard, and facilitates inclusion of RxNorm identifiers in electronic health records.
  • Efficient data entry - RxTerms separates the full names in RxNorm into two parts: drug name + route (e.g. INDERAL (Oral-pill)) and strength + dose form (e.g. 80 MG Tabs) to avoid big picklists with excessively long names. It excludes drugs from RxNorm that are obsolete or unavailable in the U.S.* Try it here.
  • User-friendly features - commonly used synonyms and abbreviations (e.g. HCTZ for hydrochlorothiazide), "tall man" lettering recommended by FDA to avoid medication errors (e.g. ChlorproMAZINE and ChlorproPAMIDE).
  • Good coverage - retains the broad coverage of RxNorm for U.S. prescribable drugs - 99% coverage of both generic and brand names of U.S. most commonly prescribed drugs. RxTerms is tailored for U.S. prescribing and it might not be the right choice for many non-U.S. countries.

CMS is using RxTerms in a demonstration project of its post-acute care assessment tool (CARE). At NLM, we will also use RxTerms in our NLM Personal Health Record. We encourage anyone who needs a drug interface terminology to try it.

To learn more about the RxTerms data, click here.

To download the RxTerms files, click here.

To see a presentation on RxTerms, click here.

RxTerms is developed and maintained by Kin-Wah Fung of the Lister Hill National Center for Biomedical Communications, NLM. Please directly email comments or questions to: or enter them here.

*Drugs not associated with any NDC codes in RxNorm are assumed to be unavailable in the U.S. This is an approximation and may not be 100% accurate.

Last reviewed: 22 October 2008
Last updated: 22 October 2008
First published: 21 October 2008
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