In this system, drugs are classified into groups at 5 different levels:
The first level of the code is based on a letter for the anatomical group and consists of one letter; there are 14 main groups:
|A||alimentary tract and metabolism|
|B||Blood and blood forming organs|
|G||Genito-urinary system and sex hormones|
|H||Systemic hormonal preparations, excluding sex hormones and insulins|
|J||Anti-infectives for systemic use|
|L||Antineoplastic and immunomodulating agents|
|P||Antiparasitic products, insecticides and repellents|
The second level of the code is based on the therapeutic main group and consists of two digits.
The third level of the code is based on the therapeutic/pharmacological subgroup and consists of one letter.
The fourth level of the code is based on the chemical/therapeutic/pharmacological subgroup and consists of one letter.
The fifth level of the code is based on the chemical substance subgroup and consists of two digits.