WHO Drug Dictionary


The WHO Drug Dictionary is an international classification of medicines created by the WHO Programme for International Drug Monitoring and managed by the Uppsala Monitoring Centre.
It is used by pharmaceutical companies, clinical trial organizations and drug regulatory authorities for identifying drug names in spontaneous ADR reporting and in clinical trials. Created in 1968 and regularly updated, since 2005 there have been major developments in the form of a WHO Drug Dictionary Enhanced and a WHO Herbal Dictionary, which covers traditional and herbal medicines. Since 2016 all of the WHODrug products have been available in a single subscription service called WHODrug Global.

Organization

WHODrug drug code consist of 11 characters. It has 3 parts: Drug Record Number, Sequence number 1 and Sequence number 2. DrgRecNo consists of 6 characters. It uniquely identifies active moieties, regardless of salt form or plant part and extract.
Seq1 is used to uniquely identify different variations, plant parts and extraction methods, thereby defining active substances or a combination of active substances. WHODrug records sharing the same DrugRecNo and Seq1 contain the same variation/plant part/extract variation of the same active moiety. For single-ingredient records, Seq1=01 identifies a specific active moiety. If Seq1 is higher than 01 it refers to variations of that active moiety. For multi-ingredient records, Seq1=01 identifies a combination of active moieties. If Seq1 is higher than 01 it refers to variations of one or more of the active moieties in the combination. Finally, Seq2 uniquely identifies the name of the record in WHODrug.

Example

The Drug Code for the substance Ibuprofen is 001092 01 001. The Drug Code for the trade name Advil infants pain & fever relief is 001092 01 A3D.

Relationship to [Anatomical Therapeutic [Chemical Classification System]]

WHODrug records are classified with at least one code from Anatomical Therapeutic Chemical Classification System. Preferably, a fourth level ATC code is assigned. ATC assignments in WHODrug are marked as 'official' or 'UMC-assigned'. Official ATC codes are classifications included in the official ATC index, while UMC-assigned ATC codes are classifications NOT included in the official ATC index.
In addition, a separate cross reference called "Cross Reference ATC 5". In this additional reference, WHODrug records are matched to fifth level ATC codes where applicable.

Formats

WHODrug is offered in Four formats. B3 format is brief while C3 format contains additional columns on top of B3 format.

Dictionary Versions

The WHO Drug Dictionary has previously been abbreviated as "WHODRL" by Saurabh Saxena and may still be referenced as such.

Standardised Drug Groupings

WHODrug concepts can be organized into groups. Standardised Drug Groupings define groups of drugs. For example, diuretics, costicosteroids, drugs used in diabetes. Groups are also defined based on interaction, for example, drugs interacting with CYP2C8 or drugs interacting with UGT.