Additional file 2 of Dispensations of benzodiazepines, z-hypnotics, and gabapentinoids to patients receiving opioid agonist therapy; a prospective cohort study in Norway from 2013 to 2017 VoldJørn Henrik SkurtveitSvetlana AasChrister ChalabianlooFatemeh KlosterPia Synnøve JohanssonKjell Arne FadnesLars Thore 2020 Additional file 2. Anatomical Therapeutic Chemical (ATC) codes for opioids, benzodiazepines, z-hypnotics and gabapentinoids. Legends: OAT = opioid agonist therapy, and WHO = World Health Organization. * Defined by the WHO collaborating centre for drug statistics. The table displays ATC codes and the corresponding drugs defined by WHO.