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Unified Medical Language System (UMLS)

UMLS Vocabularies

MED-RT (Medication Reference Terminology) - Source Representation

This page lists specific source data elements and provides information on their representation in the UMLS Metathesaurus.

Summary of Changes:

There have been no changes to the MED-RT release format or Metathesaurus source processing.

Source Provided Files:

All source files, including documentation, are available on the MED-RT download site:

File Description
Core_MEDRT_YYYY.MM.DD_XML.xml Data file
MED-RT Documentation.pdf Documentation
MED-RT_Schema_v1.xsd XML schema definition

Source-Provided Data: Details

The following data is processed for the UMLS; some element values are implied or redundant and are not directly processed


Element Description Representation
<name> Fully-specified concept name, including Concept Type suffix MRCONSO.STR, TTY = FN
<code> Code in source identifier MRCONSO.CODE, MRCONSO.SDUI
<status> Status MRSAT.ATN = STATUS, ATV = A
<property><name> = CTY Concept type: a category or label assigned only to every concept owned by MEDRT. Valid CTY values include:
  • EPC - FDA SPL established pharmacologic class
  • APC - additional pharmacologic class
  • MoA - mechanism of action
  • PE - physiologic effect
  • TC - therapeutic category
  • PK - pharmacokinetics
  • EXT - local terminology extensions
  • HC - local hierarchical concept to aggregate subconcepts, alphabetically or conceptually
<property><name> = NUI Alphanumeric unique concept identifier MRCONSO.CODE, MRCONSO.SDUI (same as "code" value)
<synonym><name> Valid values are: "Preferred Term" or "Synonym"; corresponds to <preferred> = true MRCONSO.TTY = PT or SY as indicated
<synonym><to_name> Every concept may have zero or more synonymous names MRCONSO.STR; TTY = SY
<synonym><preferred> Valid values are: "true" or "false"; corresponds to "Preferred Term" or "Synonym" values MRCONSO.STR; TTY = SY


MED-RT association name MRREL.REL MRREL.RELA/RELA inverse Target concept terminology or CTY
CI_ChemClass RO contraindicated_class_of/has_contraindicated_class MeSH
CI_MoA RO contraindicated_mechanism_of_action_of/has_contraindicated_mechanism_of_action CTY: MoA
CI_PE RO contraindicated_physiologic_effect_of/has_contraindicated_physiologic_effect CTY: PE
CI_with RO contraindicated_with_disease/has_contraindicated_drug MeSH
Parent Of PAR/CHD parent_of/has_parent; associations between two MED-RT concepts are used to build a MED-RT-only hierarchy. Parent/Child relationships involving concepts in other sources are not included in the hierarchy, they are only included as pairwise relationships in MRREL.RRF CTY: same CTY as concept of origin (e.g., MoA, PE, EPC, PK, TC, EXT) if MED-RT target, or Target: SNOMED CT US Edition or MeSH if mapped into external terminology hierarchy
effect_may_be_inhibited_by RO effect_may_be_inhibited_by/may_inhibit_effect_of MeSH
has_MoA RO has_mechanism_of_action/mechanism_of_action_of CTY: MoA
has_PE RO has_physiologic_effect/physiologic_effect_of CTY: PE
has_PK RO has_pharmacokinetics/pharmacokinetics_of CTY: PK
has_SC RO has_structural_class/structural_class_of MeSH
has_TC RO has_therapeutic_class/therapeutic_class_of CTY: TC
has_active_metabolites RO has_active_metabolites/active_metabolites_of MeSH
induces RO induces/induced_by MeSH
may_diagnose RO may_diagnose/may_be_diagnosed_by MeSH
may_prevent RO may_prevent/may_be_prevented_by MeSH
may_treat RO may_treat/may_be_treated_by MeSH
site_of_metabolism RO site_of_metabolism/metabolic_site_of CTY: PK
Synonym Of SY SNOMED CT US Edition or MeSH
Element Description Representation
<from_namespace> Values are: MED-RT, MeSH, RXNORM SAB of MRREL.AUI
<from_code> Code in specified from_namespace (note: a small number of from_code values are invalid in the designated namespace; these are not processed) CODE or SCUI referenced by MRREL.AUI
<to_namespace> Values are: MED-RT, MeSH, RXNORM, SNOMED-CT SAB of MRREL.AUI
<to_code> Code in specified to_namespace (note: a small number of to_code values are invalid in the designated namespace; these are not processed) CODE or SCUI reference by MRREL.AUI
<qualifier><name> = Authority All MED-RT relationships have an Authority qualifier which contains the acronym of its asserting source authority. Conflicting relationships from different authorities can co-exist in the knowledge base. Valid relationship source authorities are:
  • MEDRT - relationship asserted by legacy NDF-RT subject matter experts or by MED-RT
  • FMTSME - relationship recommended by FMT subject matter experts for SPL
  • FDASPL - relationship assigned by FDA SPL to active ingredient moieties
  • NLMUMLS - relationship assigned by NLM to terminology concepts in the UMLS Metathesaurus