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Unified Medical Language System (UMLS)

UMLS Vocabularies

NDDF (FDB MedKnowledge) - Synopsis

Web site:

FDB MedKnowledge, formerly National Drug Data File (NDDF) Plus, is produced by First DataBank.

FDB MedKnowledge combines a comprehensive set of drug database elements, drug pricing and clinical information with multiple types of unique drug identifiers to allow flexibility in representing drugs and health conditions, enhancing clinical decision support.

FDB MedKnowledge encompasses medications approved by the U.S. Food and Drug Administration, and information on commonly-used over-the-counter and alternative therapy agents such as herbals, nutraceuticals and dietary supplements.

Metathesaurus Scope
The Metathesaurus representation of FDB MedKnowledge includes only clinical drugs, dose forms, and ingredients.

The Metathesaurus representation of FDB MedKnowledgecontains approximately 32,683 clinical drugs, 839 dose forms, and 14,579 ingredients.

Update Frequency
FDB MedKnowledge is updated weekly.

Metathesaurus Update Frequency
FDB MedKnowledge is updated in each Metathesaurus release as part of RxNorm.

Sites Consulted

  1. National Drug Data File (NDDF) Plus™. San Bruno (CA): First Databank, Inc. National Drug Data File (NDDF) Plus™; [cited 2010 Nov 22]. Available from: