ATC code R Respiratory system is a section of the Anatomical Therapeutic Chemical Classification System, a system of alphanumeric codes developed by the World Health Organization (WHO) for the classification of drugs and other medical products.[1][2][3][4]
Codes for veterinary use (ATCvet codes) can be created by placing the letter Q in front of the human ATC code: for example, QR.[5]
National issues of the ATC classification may include additional codes not present in this list, which follows the WHO version.