The ATC/DDD system provides an international standard for drug utilization research, assisting in the comparison and presentation of drug consumption statistics across various levels. It classifies drugs based on their main therapeutic use and assigns defined daily doses (DDD) to facilitate the measurement of drug use, though it is not intended for decisions regarding pricing or reimbursement. Additionally, the system includes general principles for classification, suggests methods for expressing drug exposure, and acknowledges limitations in pediatric dosing assignment.

1. Apr 12, 2016
Dr. AMREEN SABA
ATTARIYA
Dr.ASA:ATC/DDD Date: 09/Apr/16
POST GRADUATE STUDENT
DEPT OF PHARMACOLOGY
M.R. MEDICAL COLLEGE, GULBARGA
INDIA

2. Outline
The ATC/DDD methodology
Definition, Purpose, Structure
And Principles
Real world applications of ATC/DDD.
DU90%
Electronic Prescribing
Summary
References
Apr 12, 2016Dr.ASA:ATC/DDD

3. ATC/DDD???
ATC (Anatomical Therapeutic Chemical) Classification
Don’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
Apr 12, 2016
Introduction to Drug Utilization Research, WHO 2003
Dr.ASA:ATC/DDD

4. Main Purpose
“International language for Drug Utilisation(DU)
research”
Tool for presenting DU researchimprove
quality of drug use
Presentation & comparison of drug consumption
statistics at national & international level.
Apr 12, 2016Dr.ASA:ATC/DDD

5. Drawback
Not suitable for guiding decisions about
Reimbursment
Pricing
Therapeutic substitution
Apr 12, 2016Dr.ASA:ATC/DDD

6. 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.
Apr 12, 2016Dr.ASA:ATC/DDD

7. The WHO Collaborating Centre for Drug
Statistics Methodology
Established in 1982 in OSLO.
In 1996WHO 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).
Apr 12, 2016Dr.ASA:ATC/DDD

8. Main activities of WHO Centre
To classify drugs according to the ATC system and
assign DDDs
Review and revise as necessary.
Stimulate and influence the practical use of the system
Organize training courses in the ATC/DDD
methodology
Provide technical support to countries in setting up
national medicines classification system.
Apr 12, 2016Dr.ASA:ATC/DDD

9. ATC Main Group(14)
A- Alimentary Tract And Metabolism
B-Blood And Blood Forming Organs
C- Cardiovascular System
D- Dermatologicals
G -Genito Urinary System And Sex Hormones
H -Systemic Hormonal Preparations, Excl. Sex Hormones And Insulins
J- Antiinfectives For Systemic Use
L- Antineoplastic And Immunomodulating Agents
M- Musculo-skeletal System
N- Nervous System
P- AntiParasitic Products, Insecticides And Repellents
R- Respiratory System
S- Sensory Organs
V- Various Apr 12, 2016Dr.ASA:ATC/DDD

10. Structure of ATC Code
Apr 12, 2016
ANATOMICAL
MAIN GROUP
THERAPEUTIC
MAIN GROUP
THERAPEUTIC
SUBGROUP
PHARMACOLOGICAL
SUBGROUP
CHEMICAL SUBSTANCE
SUBGROUPDr.ASA:ATC/DDD

11. General Principles for ATC
Classification
Drugs are classified based on their main therapeutic use
Only one ATC code for each ROA
Several ATC codes: if
Clearly different therapeutic uses reflected in different
– Routes of administration (e.g. topical, systemic)
– Strengths
Apr 12, 2016Dr.ASA:ATC/DDD

12. “Simple” Codes
Apr 12, 2016Dr.ASA:ATC/DDD

13. Different Indication – One ATC Code
Apr 12, 2016Dr.ASA:ATC/DDD
N06AX21

14. Several ATC codes – “one indication”
Apr 12, 2016Dr.ASA:ATC/DDD

15. Several ATC Codes – Different
Administration Forms and Therapeutic Use
Apr 12, 2016Dr.ASA:ATC/DDD

16. OTHER ATC CLASSIFICATION SYSTEMS
ATCvet classification
ATC herbal classification
Apr 12, 2016Dr.ASA:ATC/DDD

17. Defined Daily Dose (DDD)
Assumed Average Maintenance Dose
Per Day For A Drug Used For Its
Main Indication In Adults.
Apr 12, 2016Dr.ASA:ATC/DDD

18. DDD is nearly always a compromise
based on a review of the available
information including doses used in
various countries.
Apr 12, 2016Dr.ASA:ATC/DDD

19. DDD is sometimes a dose that is rarely if
ever prescribed, because
it is an AVERAGE of two or more
commonly used dose sizes.
Apr 12, 2016Dr.ASA:ATC/DDD

20. Concept of DDD
A technical unit of measurement, represents an
“average” daily dose for the main indication
For measuring & comparing volume of drug
use
Should not be interpreted as the RDA/PDD
Reflects global dosage irrespective of genetic
variations.
Rough estimate of consumption & not an exact
picture of actual use Apr 12, 2016Dr.ASA:ATC/DDD

21. 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)
Apr 12, 2016Dr.ASA:ATC/DDD

22. Sources Used When Assigning DDDs
Approved dose recommendations for the main
indication
Submitted documentation from the applicant,
textbooks, and data from clinical trials
Apr 12, 2016Dr.ASA:ATC/DDD

23. Commonly Used Measures To
Express Drug Exposure In DDD
DDDs/1000 inhabitants/day
DDDs /100 bed-days
DDDs /inhabitants /year
Apr 12, 2016Dr.ASA:ATC/DDD

24. DDDs/1000 inhabitants/day
Ex: 10 DDDs/1000 inhabitants/day
1% of the population can receive a
certain treatment daily
Apr 12, 2016Dr.ASA:ATC/DDD

25. DDDs /100 bed days
When 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.
Apr 12, 2016Dr.ASA:ATC/DDD

26. DDDs/1000 inhabitants/year
Estimate of the average number of days
for which each inhabitant is treated
annually
Apr 12, 2016Dr.ASA:ATC/DDD

27. Selection of units
g
mg
mcg
mmol
U(unit)
TU(thousand U)
MU(million U)
UD(unit dose)for combination products Apr 12, 2016Dr.ASA:ATC/DDD

28. Codes for Route Of Administration
Inhal = Inhalation
R = Rectal
N = Nasal
SL = Sublingual/buccal/oromucosal
O = Oral
TD = Transdermal
P = Parenteral
V = Vaginal
Apr 12, 2016Dr.ASA:ATC/DDD

29. Pediatric DDD
DDDs 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
Apr 12, 2016Dr.ASA:ATC/DDD

30. Applications of ATC/DDD
Drug utilization and pharmacoepidemiology
– PVG
– Regulatory intervention and impact of drug
use
Apr 12, 2016Dr.ASA:ATC/DDD

31. Apr 12, 2016Dr.ASA:ATC/DDD

32. ATC/DDD in DU Research
Study patterns of use and changes over time
Evaluate the impact of information efforts,
regulatory changes etc.
Study drug exposure in relation to ADR
Indicate over-use, under-use and misuse/abuse of
drugs
Defines need for further pharmacoepidemiology
studies
Apr 12, 2016Dr.ASA:ATC/DDD

33. 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.
Apr 12, 2016Dr.ASA:ATC/DDD

34. 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.
Apr 12, 2016
Dr.ASA:ATC/DDD
*Bergman ULF. Pharmacoepidemiology- from description to quality assessment:
A Swedish perspective. Norwegian Journal of Epidemiology 2001;11(1):31-6

35. Apr 12, 2016Dr.ASA:ATC/DDD

36. 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 DRUGS
Apr 12, 2016Dr.ASA:ATC/DDD*WHO Drug Information Vol. 16, No. 3, 2002

37. SYSTEM INCLUDES:
Information and recommendations from
Regional and local drug committees in the county
Recent guidelines from the medical products
agency
Links to the physicians desk reference
Recent drug news with comments and evaluations
by specialists.
Apr 12, 2016Dr.ASA:ATC/DDD

38. Apr 12, 2016Dr.ASA:ATC/DDD

39. Apr 12, 2016Dr.ASA:ATC/DDD

40. Apr 12, 2016Dr.ASA:ATC/DDD

41. Apr 12, 2016Dr.ASA:ATC/DDD

42. Summary
ATC/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 time
Apr 12, 2016Dr.ASA:ATC/DDD

43. References
www.whocc.no
Annual ATC/DDD courses in Oslo, Norway
Guidelines for ATC classification and DDD
assignment 2016.
Apr 12, 2016Dr.ASA:ATC/DDD