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The drug exposure domain concepts capture records about the utilization of a Drug when ingested or otherwise introduced into the body. A Drug is a biochemical substance formulated in such a way that when administered to a Person it will exert a certain physiological or biochemical effect. The following products are not considered Drugs, but Devices:
Drug domain Concepts should be used in the drug_concept_id of the DRUG_EXPOSURE the DRUG_ERA and the DOSE_ERA (both only at the Ingredient level) tables, or in the value_as_concept_id field of the OBSERVATION or MEASUREMENT table (e.g. for observations like “Plasma level”).
Structure of Drug Domain
Standard Concepts are taken from the RxNorm and RxNorm Extension vocabularies. All Standard RxNorm and RxNorm Extension Concepts can be used in the drug_concept_id fields.
RxNorm is the foundation for the combined Domain space. All valid RxNorm Concepts (invalid_reason is null) are used as Standard Concepts. However, RxNorm only contains Drug Concepts for products sold in the United States. All Concepts derived from international products are availabe in the RxNorm Extension vocabulary. Apart from the different vocabulary_id, both RxNorm and RxNorm Extension for a common Drug Universe with identical rules for relationships and Concept Ancestry.
RxNorm and RxNorm Extension Concepts are hierarchical. Therefore the Concepts can also be used as Class Concepts: descendants of any Standard Concept in the CONCEPT_ANCESTOR table can expected to be a correct semantic match in a query. For example, a query for the descendants of an ingredient should turn up all drug products (Clinical Drug or Branded Drug) containing that ingredient.
On top of this combined RxNorm/RxNorm Extension Drug Domain are drug classification systems. These are derived from a variety of different vocabularies. Note: Any classification Concept may exist in different classifications, and therefore cannot be considered as unique. For example, NSAID Analgesics exist with very similar memberships as ETC, VA Class and SNOMED classes.
The Concept Classes for the drugs in the Drug Domain are based on RxNorm, and those for the Drug Classification based on that of the source vocabulary:
Vocab | Name | Ingre dient | Drug strength | Dose form | Brand name | Quantity factor | Box size | Pack content | Supplier |
---|---|---|---|---|---|---|---|---|---|
RxNorm | Ingredient | x | |||||||
Clinical Drug Component | x | x | |||||||
Clinical Drug Form | x | x | |||||||
Clinical Drug | x | x | x | ||||||
Branded Drug Component | x | x | x | ||||||
Branded Drug Form | x | x | x | ||||||
Branded Drug | x | x | x | x | |||||
Clinical Pack | x | x | |||||||
Branded Pack | x | x | x | ||||||
Rxnorm (not explicit) | Quantified Clinical Drug | x | x | x | x | ||||
Quantified Branded Drug | x | x | x | x | x | ||||
RxNorm Extension | Clinical Drug Box | x | x | x | x | ||||
Branded Drug Box | x | x | x | x | x | ||||
Quantified Clinical Box | x | x | x | x | x | ||||
Quantified Branded Box | x | x | x | x | x | x | |||
Clinical Pack Box | x | x | x | x | |||||
Branded Pack Box | x | x | x | x | x | ||||
Marketed Product | x | x | x | optional | optional | optional | optional | x | |
ATC | ATC 1st | Highest level ATC class |
All Source Vocabularies are mapped to the RxNorm Standard Concepts, and Multilex and DMD also to the DMD Standard Concepts. The mapping is either constructed from the vocabulary source and in some cases curated by the vocabulary team.
All these are provided by RxNorm.
These are manually curated by the vocabulary team
This is provided by the UMLS.
These are inferred from public source and curated by the vocabulary team.
These are inferred from public source and curated by the vocabulary team.
All relationships provided by RxNorm are loaded as is, but renamed to follow the relationship_id formatting rules and allow for bi-directional mappings, see RxNorm. All internal relationships of DMD are derived from the source and converted to generate “pseudo”-RxNorm relationship, omitting the Drug Form and Drug Component Concepts. See DMD for details. All hierarchical relationships of the drug classes are loaded for the source as is and used to form the CONCEPT_ANCESTOR table.