My note of WHODrug

WHODrug contains two entry types:

1. Preferred Name: Non-proprietary name for single-ingredient drugs or the first reported drug name of a given ingredient combination (generic name)

2. Synonym Name: Any subsequently reported drugs that are sorted under the preferred name (trade names)

WHODrug drug code

Each WHODrug entry will have a WHODrug drug code. WHODrug drug code consists of 11 characters (alphanumeric code). It has 3 parts: Drug Record Number (Drug Rec No), Sequence number 1 (Seq1), and Sequence number 2 (Seq2).

1. Drug Rec No: Active moiety (6 digits)

2. Seq 1: Different variations (salt/ester) (2 digits)

3. Seq 2: name of record in WHODrug (3 digits)

WHODrug ATC code

Each WHODrug entry will have one or more ATC codes. ATC is the Anatomical Therapeutic Chemical classification system. ATC hierarchy has 5 levels:

1. ATC 1: Anatomical main group

2. ATC2: Therapeutic subgroup

3. ATC 3: Pharmacological subgroup

4. ATC 4: Chemical subgroup

5. ATC 5: Chemical substance (Not all WHODrug entries have ATC 5.)

An example - Ibuprofen

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.

The ATC 5 code is C 03 C A 01

(For more detailed explanation, I recommend the Wiki page of WHODrug and ATC.)