RXNORM ATC4 CODE
A Biological Qualifier (BQ) is not part of the INN and the introduction of a new BQ will not have any implication on the ATC code for the specific INN.If INN names are not assigned, USAN (United States Adopted Name) or BAN (British Approved Name) are usually chosen. I n ternational nonproprietary names (INN) are preferred.Thus, in the ATC system all plain metformin preparations are given the code A10BA02. The complete classification of metformin illustrates the structure of the code: Aīlood glucose lowering drugs, excl.
The 2nd, 3rd and 4th levels are often used to identify pharmacological subgroups when that is considered more appropriate than therapeutic or chemical subgroups. The 3rd and 4th levels are chemical, pharmacological or therapeutic subgroups and the 5th level is the chemical substance. Each ATC main group is divided into 2nd levels which could be either pharmacological or therapeutic groups.
The system has fourteen main anatomical/pharmacological groups or 1st levels. I n the ATC classification system, the active substances are classified in a hierarchy with five different levels.