Sections: WHO Model List of Essential Drugs


Over the years comments have been received on the way the WHO List of Essential Drugs is structured with the suggestion that it could be more logical and user-friendly. The current structure and two possible alternatives are presented. They are intended to form a basis for discussion and modification at the Expert Committee.


1. Current section arrangement, Technical Report Series 895 (2000)

2. Secretariat Proposal (2002) by alphabetic presentation or as intuitive ranking

3. Anatomical, Therapeutic, Chemical (ATC), 

    Model List according to latest ATC classification (2002) (classified by two levels only), 

    WHO 1999 Model List by ATC-code using all levels and including dosage forms

4. WHO Model Formulary (variant on the WHO Technical Report Series)



Possible section structures


1. Technical Report Series 895 (2000)

(EDM/PAR, 14 March 2002)


The current Essential Drug List is arranged in 27 sections and is further subdivided into 76 second level subsections, 23 third and four 4th level subsections.


1st level sections
2nd level subsections
3rd level subsections
4th level subsections


The Technical Report Series (TRS) Structure has been used in:

  • AFRO Essential Drugs Price Indicator 
  • ECHO, International Health Services Ltd (UK)
  • International Dispensary Association (Netherlands) 
  • International Drug Price Indicator Guide (MSH/WHO)
  • National Essential Drug Lists may follow exactly the TRS section system, may use it with slight modification or use an entirely different system. 
  • New Emergency Health Kit (1998).
  • UN Emergency Relief Items, Volume 2, Compendium of basic specifications
  • UNICEF Supply Division

2. Secretariat Proposal (2002)

A new arrangement is a proposed using 32 clinical grouping without other levels, subgroups or subsections.

Single level sections

3. Anatomical, Therapeutic, Chemical (ATC)

The ATC classification has been developed by the WHO Collaborating Centre for Drug Statistics in Oslo, Norway. The full system classifies drugs into groups at five different levels resulting in some cases in a 7 digit/letter code. There are 14 first level groups and 99 second level groups. The example given uses only the first and second levels. Essential drugs fall into 66 groups.

1st level groups

2nd level groups (99)
EDL drugs fall into 66 groups

4. WHO Model Formulary 

The WHO Model Formulary uses the same system of sections as the Technical Report series, sometimes named differently. There is more extensive use of subsections and there is much cross referencing in the text.

1st level sections

2nd level subsections

3rd level subsections

4th level subsections

Secretariat recommendation

The Secretariat is inclined to favour some form of example 2 recognizing that all systems have advantages and disadvantages.

Advantages and disadvantages of three possible EDL structures (1, 2 and 3)

1) Technical Report Series sections

Advantages Disadvantages
Already known and used Mixed pharmaceutical and pharmaceutical/clinical sections e.g. diuretics, oxytocics - gastrointestinal drugs, antiparkinsonian drugs
Alphabetic listing 4 levels of sections/subsections
Difficult to navigate and to find drugs without an index

2) Secretariat proposal

Advantages Disadvantages
Clinically  based A change causing disruption to existing systems e.g. WHO/ MSH price guide
Single level Needs special arrangements for antiinfectives?
Potentially user friendly Untried, follows no pre-existing scheme
Non alphabetic listing

3) ATC classification sections



Already known and used (but only for drug statistics?) Designed for and used for drug statistical methodologies
Comprehensive but perhaps not utilitarian for a limited number of drugs ( e.g. WHOEDL)
Perhaps not user friendly to find drugs


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