Click on a topic below the Source Synopsis section to display details.
Source Synopsis
Web site:
https://www.whocc.no/atc/structure_and_principles/
Authority
The World Health Organization Collaborating Center for Drug Statistics Methodology produces and maintains the Anatomical Therapeutic Chemical Classification System with Defined Daily Doses (ATC/DDD).
The RxNorm includes ATC information only.
Purpose
ATC classifies therapeutic drugs to enable drug research and to improve the quality of drug use.
Description
ATC classifies drugs at five different levels. Each level is a different grouping of drugs. Groupings of active substances include the organ or system on which the drug acts as well as therapeutic, pharmacological, and chemical properties of the drug.
RxNorm Scope
The RxNorm representation of ATC includes ingredients and drug classes.
Update Frequency
ATC is updated annually.
RxNorm Update Frequency
ATC is updated annually in RxNorm, typically in the February RxNorm monthly release.
Sites Consulted
- WHOCC - Home [Internet]. Oslo: WHO Collaborating Centre for Drug Statistics Methodology [updated 2018 Feb 15]. ATC/DDD methodology - History. WHOCC; c2018 [cited 2020 Oct 12]. Available from: https://www.whocc.no/atc_ddd_methodology/history/.
- WHOCC - Home [Internet]. Oslo: WHO Collaborating Centre for Drug Statistics Methodology [updated 2018 Nov 26]. ATC - Structure and Principles; [updated 2018 Feb 15; cited 2018 Dec 7]. Available from: https://www.whocc.no/atc/structure_and_principles/.
Metadata
| Field | Value |
|---|---|
| Short Name | Anatomical Therapeutic Chemical Classification System |
| Family | ATC |
| Source Restriction Level | 0 |
| Language | ENG |
| License Contact | WHO Collaborating Centre for Drug Statistics Methodology Norwegian Institute of Public Health P.O.Box 4404 Nydalen Oslo Norway 0403 +47 21 07 81 60 +47 21 07 81 46 whocc@fhi.no http://www.whocc.no/copyright_disclaimer/ |
| Content Contact | WHO Collaborating Centre for Drug Statistics Methodology Norwegian Institute of Public Health P.O.Box 4404 Nydalen Oslo Norway 0403 +47 21 07 81 60 +47 21 07 81 46 whocc@fhi.no http://www.whocc.no/ |
Source Representation
This section lists specific source data elements and provides information on their representation in RxNorm.
Summary of Changes
There are no changes to the original data format or to RxNorm source processing.
Source Provided Files:
The ATC file is available from:
https://www.whocc.no/atc_ddd_index_and_guidelines/atc_ddd_index/
The following file is used for RxNorm source processing.
|
File Name |
Description |
|
<YYYY> ATC Index with DDDs_electronic version.xlsx |
Excel file containing information on codes and levels |
Source-Provided Files: Details
The following is a list of fields in the ATC source files used in RxNorm processing and their representations in RxNorm.
Consult the ATC web site for additional ATC information at: https://www.whocc.no/atc/structure_and_principles/
File name: 2023 ATC Index with DDDs_electronic version.xlsx; only the first tab, “ATCIndeks with DDDs 2023” is processed
|
# |
ATC Field Name |
Description |
RxNorm Representation |
|
1 |
ATC Code |
1-7 character alphanumeric code for the ATC name |
RXNCONSO.CODE
RXNSAT.ATN = ATC_LEVEL Levels are implied by the number of characters in the ATC code: 1 character: Level 1 3 characters: Level 2 4 characters: Level 3 5 characters: Level 4 7 characters: Level 5
RXNREL.RRF Used to derive hierarchical relationships: Levels 1-4: REL = PAR/CHD RELA = inverse_isa/isa Level 5: REL = PAR/CHD RELA = has_member/member_of |
|
2 |
ATC level name |
ATC substance name In the ATC classification system, the active substances are classified in a hierarchy with five different levels. The system has fourteen main anatomical/pharmacological groups or 1st levels. Each ATC main group is divided into 2nd levels which could be either pharmacological or therapeutic groups. The 3rd and 4th levels are chemical, pharmacological or therapeutic subgroups and the 5th level is the chemical substance. The 2nd, 3rd and 4th levels are often used to identify pharmacological subgroups when that is considered more appropriate than therapeutic or chemical subgroups. |
RXNCONSO.STR TTY = PT for levels 1-4 TTY = IN for level 5
|
|
3 |
DDD |
Not applicable |
Not applicable |
|
4 |
Unit |
Not applicable |
Not applicable |
|
5 |
Adm.R |
Not applicable |
Not applicable |
|
6 |
Comment |
Not applicable |
Not applicable |
RxNorm Representation
This section lists RxNorm data elements and traces them back to the specific ATC data that populates them.
Summary of Changes
There are no changes to the original data format or to RxNorm source processing.
Source Provided Files:
The ATC file is available from:
https://www.whocc.no/atc_ddd_index_and_guidelines/atc_ddd_index/
The following file is used for RxNorm source processing.
|
File Name |
Description |
|
2023 ATC Index with DDDs_electronic version.xlsx |
Excel file containing information on codes and levels |
RxNorm Identifiers:
Identifiers are assigned as follows:
|
Identifier |
Origin |
|
CODE |
ATC code |
|
SAUI |
Not applicable |
|
SCUI |
Not applicable |
|
SDUI |
Not applicable |
Atoms (RXNCONSO):
|
Term Type |
Origin |
|
IN |
ATC level name for Level 5 codes |
|
PT |
ATC level name for Level 1-4 codes |
|
RXN_IN |
Created by RxNorm editors for disambiguation purposes, based on the hierarchy |
|
RXN_PT |
Created by RxNorm editors for disambiguation purposes, based on the hierarchy |
Relationships (RXNREL):
|
REL/inverse REL RELA/inverse RELA |
Origin |
|
PAR/CHD has_member/member_of |
Hierarchical relationship connecting Level 5 (chemical substance) to Level 4 subgroup (IN to PT) |
|
PAR/CHD inverse_isa/isa |
Hierarchical relationships connecting Levels 1-4 (PT to PT) |
Attributes (RXNSAT):
|
ATN |
Origin |
|
ATC_LEVEL |
Derived from ATC code:
1: main anatomical/pharmacological groups 2. Either pharmacological or therapeutic groups 3,4: Chemical, pharmacological or therapeutic subgroups 5: Chemical substance |
|
IS_DRUG_CLASS |
“Y” for PT (level 1-4) codes |
Data Examples with Sample Database Queries
This section lists source terminology specific data examples and sample database queries using Structured Query Language (SQL) to obtain the data. For more information about RxNorm data and files, see the RxNorm Technical Documentation.
Names and Codes in RXNCONSO.RRF
Here are sample source terminology code, source string, RxNorm Concept Unique Identifier (RXCUI), RxNorm string, RxNorm term type (TTY), and suppress values.
| SOURCE_CODE | SOURCE_STR | RXCUI | RXNORM_STR | RXNORM_TTY | SUPPRESS |
|---|---|---|---|---|---|
| C01EB16 | ibuprofen | 5640 | Ibuprofen | IN | N |
| G02CC01 | ibuprofen | 5640 | Ibuprofen | IN | N |
| M02AA13 | ibuprofen | 5640 | Ibuprofen | IN | N |
| M01AE01 | ibuprofen | 5640 | Ibuprofen | IN | N |
Here is a sample database query to retrieve the data above:
SELECT distinct rc1.code as source_code, rc1.str as source_str, rc1.rxcui, rc2.str as rxnorm_str, rc2.tty as rxnorm_tty, rc2.suppress
FROM rxnconso rc1, rxnconso rc2
WHERE rc1.code in ('C01EB16', 'G02CC01', 'M01AE01', 'M02AA13')
AND rc1.sab = 'ATC'
AND rc1.rxcui = rc2.rxcui
AND rc2.sab = 'RXNORM';
Names and Relationships in RXNCONSO.RRF and RXNREL.RRF
Here are sample source terminology code, source string, RXCUI, relationship name, RxNorm term type (TTY), brand name, and suppress values.
| SOURCE_CODE | SOURCE_STR | RXCUI | RELA | RXNORM_TTY | BN | SUPPRESS |
|---|---|---|---|---|---|---|
| C01EB16 | ibuprofen | 5640 | has_tradename | BN | Advil | N |
| C01EB16 | ibuprofen | 5640 | has_tradename | BN | Brufen | N |
| C01EB16 | ibuprofen | 5640 | has_tradename | BN | Motrin | N |
| C01EB16 | ibuprofen | 5640 | has_tradename | BN | Nuprin | N |
Here is a sample database query to retrieve the data above:
SELECT distinct rc1.code as source_code, rc1.str as source_str, rc1.rxcui, rr.rela, rc2.tty as rxnorm_tty, rc2.str as bn, rc2.suppress
FROM rxnconso rc1, rxnrel rr, rxnconso rc2
WHERE rc1.code = 'C01EB16'
AND rc1.sab = 'ATC'
AND rc1.rxcui = rr.rxcui2
AND rr.rela = 'has_tradename'
AND rr.rxcui1 = rc2.rxcui
AND rc2.sab = 'RXNORM'
AND rc2.tty = 'BN'
ORDER BY suppress;
Last Reviewed: April 10, 2024