anatomic therapeutic chemical classification, defined daily dose, drug utilisation

May 3, 2023

Dr. AMREEN SABA ATTARIYA

Dr.ASA:ATC/DDD Date: 09/Apr/16

POST GRADUATE STUDENT

DEPT OF PHARMACOLOGYM.R. MEDICAL COLLEGE, GULBARGA INDIA

OutlineThe ATC/DDD methodology

Definition, Purpose, Structure And Principles

Real world applications of ATC/DDD.DU90%Electronic PrescribingSummaryReferences

May 3, 2023Dr.ASA:ATC/DDD

ATC/DDD???ATC (Anatomical Therapeutic Chemical) ClassificationDon’t confuse it with Anatomical Therapeutic (AT)classification developed by European Pharmaceutical Market Research Association (EPhMRA)DDD (Defined Daily Dose) The assumed average maintenance dose per day for a drug used for its main indication in adults

May 3, 2023Introduction to Drug Utilization Research, WHO 2003

Dr.ASA:ATC/DDD

Main Purpose“International language for Drug Utilisation(DU) research”Tool for presenting DU researchimprove quality of drug usePresentation & comparison of drug consumption statistics at national & international level.


DrawbackNot suitable for guiding decisions about ReimbursmentPricingTherapeutic substitution


The Classification Of A Substance In The ATC/DDD System Is Not A

Recommendation For Use, Nor Does It Imply Any Judgments About Efficacy

Or Relative Efficacy Of Drugs & Groups Of Drugs.


The WHO Collaborating Centre for Drug Statistics

MethodologyEstablished in 1982 in OSLO.In 1996WHO recognised the use of ATC/DDD as international std for DU.Centre was until 2001 was at Norwegian Medicine Depot(NMD)From Jan 2002,shifted to Norwegian Institute Of Public Health(Dept of Pharmacoepidemiology).


Main activities of WHO Centre

To classify drugs according to the ATC system and assign DDDsReview and revise as necessary.Stimulate and influence the practical use of the systemOrganize training courses in the ATC/DDD methodologyProvide technical support to countries in setting up national medicines classification system.


ATC Main Group(14)A- Alimentary Tract And MetabolismB-Blood And Blood Forming OrgansC- Cardiovascular SystemD- DermatologicalsG -Genito Urinary System And Sex HormonesH -Systemic Hormonal Preparations, Excl. Sex Hormones And InsulinsJ- Antiinfectives For Systemic UseL- Antineoplastic And Immunomodulating AgentsM- Musculo-skeletal SystemN- Nervous SystemP- AntiParasitic Products, Insecticides And RepellentsR- Respiratory SystemS- Sensory OrgansV- Various


Structure of ATC Code

May 3, 2023

ANATOMICAL MAIN GROUP

THERAPEUTIC MAIN GROUP

THERAPEUTIC SUBGROUP

PHARMACOLOGICAL SUBGROUP

CHEMICAL SUBSTANCE SUBGROUP

Dr.ASA:ATC/DDD

General Principles for ATC Classification

Drugs are classified based on their main therapeutic useOnly one ATC code for each ROASeveral ATC codes: ifClearly different therapeutic uses reflected in different– Routes of administration (e.g. topical, systemic)– Strengths


“Simple” Codes


Different Indication – One ATC Code


N06AX21

Several ATC codes – “one indication”


Several ATC Codes – DifferentAdministration Forms and

Therapeutic Use


OTHER ATC CLASSIFICATION SYSTEMS

ATCvet classification

ATC herbal classification


Defined Daily Dose (DDD)

Assumed Average Maintenance Dose Per Day

For A Drug Used For Its Main Indication In Adults.


DDD is nearly always a compromise based on a review of the available

information including doses used in various countries.


DDD is sometimes a dose that is rarely if ever prescribed, because

it is an AVERAGE of two or more commonly used dose

sizes.


Concept of DDDA technical unit of measurement, represents an “average” daily dose for the main indicationFor measuring & comparing volume of drug useShould not be interpreted as the RDA/PDDReflects global dosage irrespective of genetic variations.Rough estimate of consumption & not an exact picture of actual use


Principles for DDD assignment

One DDD per ROA within an ATC code.DDD will NOT be assigned unless a product is approved & marketed in at least one country.For substances indicated for rare disorders with individual dosing DDD may not be assigned.DDDs for herbal medicinal products are not included in the ATC index(published in an ATC sorted list on the website www.whocc.no)


Sources Used When Assigning DDDs

Approved dose recommendations for the main indicationSubmitted documentation from the applicant, textbooks, and data from clinical trials


Commonly Used Measures To Express Drug Exposure In DDD

DDDs/1000 inhabitants/day

DDDs /100 bed-daysDDDs /inhabitants /year


DDDs/1000 inhabitants/day

Ex: 10 DDDs/1000 inhabitants/day

1% of the population can receive a certain treatment daily


DDDs /100 bed daysWhen drug use by inpatients.Ex: 70 DDDs /100 bed days of hypnotics

70% of the inpatients might receive a DDD of a hypnotic every day.Useful for benchmarking in hospitals.


DDDs/1000 inhabitants/year

Estimate of the average number of days for which each inhabitant is treated annually


Selection of unitsgmgmcgmmolU(unit)TU(thousand U)MU(million U)UD(unit dose)for combination products


Codes for Route Of Administration

Inhal = Inhalation

R = Rectal

N = Nasal

SL = Sublingual/buccal/oromucosal

O = Oral

TD = Transdermal

P = Parenteral

V = Vaginal


Pediatric DDDDDDs are normally assigned based on use in adults.For medicinal products approved for use in children, the dose recommendations will differ based on AGE & BW.

Pediatric DDDs cant be assigned


Applications of ATC/DDD

Drug utilization and pharmacoepidemiology– PVG– Regulatory intervention and impact of drug use


ATC/DDD in DU ResearchStudy patterns of use and changes over timeEvaluate the impact of information efforts, regulatory changes etc.Study drug exposure in relation to ADRIndicate over-use, under-use and misuse/abuse of drugsDefines need for further pharmacoepidemiology studies


DU90%Innovative approach to assess drug prescription.

Assumption: Low Number Of Drugs Prescribed Is Associated With More Rational Prescribing Practices.Does not directly reflect the quality of prescription.


Used for exploring drug prescription in a rapid, effective and inexpensive way.Reflects the number of drugs that account for 90% of drug prescriptions & the adherence to local or national prescription guidelines in this segment.


*Bergman ULF. Pharmacoepidemiology- from description to quality assessment:A Swedish perspective. Norwegian Journal of Epidemiology 2001;11(1):31-6

ELECTRONIC PRESCRIBING*In Stockholm, a computer-based

prescription support system, JANUS telepharmacology, has been developed.Aims at providing all prescribers within a country with

• EASILY ACCESSIBLE • CLINICALLY RELEVANT

• UPDATED INFORMATION ON DRUGSMay 3, 2023Dr.ASA:ATC/DDD*WHO Drug Information Vol. 16, No. 3, 2002

SYSTEM INCLUDES:Information and recommendations from

Regional and local drug committees in the countyRecent guidelines from the medical products agencyLinks to the physicians desk referenceRecent drug news with comments and evaluations by specialists.


SummaryATC/DDD system is “the gold standard” for international DU research

Tool for exchanging and comparing data on drug use at local, national or international levels.

This system is itself not suitable for guiding decisions about reimbursement, pricing etc

DDD-is assumed average maintenance dose in adults & shouldn’t be confused with PDD/RDA.

Units of DDD.

Pediatric DDD cannot be assigned.

DU90% identifies the number of drugs making upto 90% of the total volume measured in DDD or number of prescription (NP), during a certain period of timeMay 3, 2023Dr.ASA:ATC/DDD

Referenceswww.whocc.noAnnual ATC/DDD courses in Oslo, NorwayGuidelines for ATC classification and DDD assignment 2016.


http://www.whocc.no/

anatomic therapeutic chemical classification, defined daily dose, drug utilisation

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