INTRODUCTION TO ATC CODING
The Anatomical Therapeutic Chemical (ATC) classification system is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological, and chemical properties. Its purpose is to improve the quality of drug use as a drug use monitoring and research tool. It does not imply a recommendation or efficacy of any medicine. It is maintained by the World Health Organization's Collaborating Center for Pharmaco-statistical Methods (WHOCC) and was first published in 1976.
CODING SYSTEM
Structure and nomenclature
This drug coding system classifies drugs into different groups according to the organ or system they act on, their therapeutic intent or properties, and their chemical properties. Different brands have the same code if they have the same active ingredients and indications. Each lowest ATC code represents a substance or combination of substances that is pharmaceutically used for a single indication (or use).
The ATC classification system is strictly hierarchical. This means that all codes have a parent code, except for the 14 top-level codes that have no parent code. A code is a semantic identifier. That is, the code itself represents information that does not act as an identifier (that is, the code itself represents the complete lineage of parent-child relationships).
HISTORY
Inspired by this interest, the Anatomical Therapeutic Chemical (ATC) classification was developed in Norway as a modification and extension of the European Pharmaceutical Market Research Association (EphMRA) classification system.
To measure drug use, it is important to have both a classification system and a unit of measure. To address objections to traditional units of measurement, a technical unit of measurement called the defined daily dose (DDD) was developed for use in drug use research.
Decades of experience with the ATC/DDD methodology have demonstrated its suitability for drug consumption monitoring and research. An increase in the number of users shows the usefulness of the system.
Purpose of the ATC/DDD system
The purpose of the ATC/DDD system is to serve as a drug use monitoring and research tool to improve the quality of drug use. Part of this is the presentation and comparison of drug use statistics at the international and other levels.
An important goal of drug use is to monitor rational and irrational drug use as an important step to improve the quality of drug use. Classification of substances in the ATC/DDD system is therefore not a recommendation for use and does not imply an assessment of the efficacy or relative efficacy of drugs and drug groups.
CLASSIFICATION
Medicinal products are classified according to the main therapeutic use of the main active ingredient.The ATC system is, however, not strictly a therapeutic classification system.
In many ATC main groups, pharmacological groups have been assigned on the 2nd, 3rd and 4th levels allowing drugs with several therapeutic uses to be included without specifying the main indication.
In this system, drugs are grouped into 5 different levels.
LEVEL 1:
The first level of the code indicates the major anatomical groups and consists of one letter. There are 14 main groups.
Example: C Cardiovascular system
Figure:1 Various ATC codes are grouped according to the organ they act on and their therapeutic, pharmacological, and chemical properties
LEVEL 2:
The second level of code indicates the treatment subgroup and consists of two digits.
Example: C03 Diuretics
Figure: 2 Dendrograms represent the anatomical therapeutic chemistry (ATC) drug hierarchy and coverage of different drug classes within the ChEMBL in vivo dataset.
LEVEL 3:
The third level of the code indicates the therapeutic/pharmacologic subgroup and consists of one letter.
Example: C03C Diuretics
LEVEL 4:
The fourth level of the code indicates the chemical/therapeutic/pharmacological subgroup and consists of one letter.
Example: C03CA Sulfonamide
LEVEL 5:
The fifth level of the code indicates the chemical substance and consists of two digits.
Example: C03CA01 Furosemide
APPLICATION FOR ATC CODES
Data requirements when applying for an ATC code for a substance, the following data must be submitted:
Relationship between chemical structure and analogous drugs.
Pharmacology and mechanism of action and relationship to analogous drugs.
The primary indications are listed in the product information for the major countries in which it has been approved or submitted for approval.
Other indications approved or proposed for approval in the future.
Proposed ATC classification with justification based on evidence provided marketing authorization status.
Information regarding therapeutic use.
Substances meeting any of the following criteria are normally included in the ATC system:
New chemical or biological substances proposed for licensing. New chemicals are generally not included in the ATC system until at least one country is ready for a marketing authorization application.
A well-defined existing chemical entity with a marketing authorization approved in one or more countries. It is desirable to set the INN (International Nonproprietary Names) for the substance. Alternatively, you should be able to use other official names, such as USAN (United States Adopted) or BAN (British Approved) names.
Herbal medicinal products that have been evaluated and approved by a regulatory authority according to a dossier containing efficacy, safety and quality data (e.g. procedures established in the EU).
Other drugs will be considered on a case-by-case basis. Complementary, homoeopathic, and herbal traditional medicines are generally not included in the ATC system.
Only one ATC code per route of administration:
Drugs are classified by primary therapeutic use or pharmacological class on the basis that there is only one ATC code per route of administration (e.g. oral formulations of similar ingredients and strength have the same ATC code) . This is a key principle of ATC classification as it allows data aggregation in drug application oversight and research without the need to count drugs multiple times. This principle is strictly enforced by the WHO Center so that users in different countries can classify medicines in the same way (defined by active ingredient, route of administration and strength).
CONCLUSION
In conclusion, the Anatomical Therapeutic Chemical (ATC) classification system provides unique codes assigned to drugs according to the organ or system they act on and their mechanism of action. Drugs are classified into groups at five different levels. The classification system is maintained by the World Health Organization (WHO).
ATC follows guidelines when creating new codes for newly approved drugs. Submit ATC classification and DDD assignment to WHO. As the available medicines and their uses continue to change and expand, regular revisions of the ATC system will always be required.
REFERENCE
Zhongyang Liu, Feifei Guo, Jiangyong Gu, Yong Wang, Yang Li, Dan Wang, Liang Lu, Dong Li, Fuchu He, Similarity-based prediction for Anatomical Therapeutic Chemical classification of drugs by integrating multiple data sources, Bioinformatics, Volume 31, Issue 11, 1 June 2015, Pages 1788–1795, https://doi.org/10.1093/bioinformatics/btv055
Kury, Fabrício. "Scrape Anatomical-Therapeutic-Chemical (ATC) classes from the WHO Collaborating Centre for Drug Statistics Methodology website", assessed 26 February 2023.
Coding System: https://en.wikipedia.org/wiki/Anatomical_Therapeutic_Chemical_Classification_System
Purpose of the ATC/DDD system". WHO Collaborating Centre for Drug Statistics Methodology, assessed 26 February 2023.
Drug Examples: https://dev.drugbank.com/guides/terms/atc-codes
Figure 1: https://www.google.com/url
Figure 2: https://journals.plos.org/ploscompbiol/article/figure?id=10.1371/journal.pcbi.
Application for ATC Code: https://www.whocc.no/atc/structure_and_principles/
Student Name: Syeda Saniya Ifteqar
Student ID: 035/022023
Qualification: Pharm. D
e-Mail ID: sania.ifteqar27@gmail.com
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