atcvet code qn51 atcvet code qn51 atcvet code qn51 products for animal euthanasia is a therapeutic subgroup of the anatomical therapeutic chemical classification system for veterinary medicinal products, a system of alphanumeric codes developed by the world health organization (who) for the classification of drugs and other medical products for veterinary use. subgroup qn51 is part of the anatomical group qn nervous system. atc codes n nervous system n01 anesthetics n02 analgesics n03 antiepileptics n04 anti-parkinson drugs n05 psycholeptics n06 psychoanaleptics n07 other nervous system drugs atcvet only qn51 products for animal euthanasia a b c d g h qi j l m n p r s v national issues of the atc classification may include additional codes not present in this list, which follows the who version. qn51a products for animal euthanasia qn51aa barbiturates qn51aa01 pentobarbital qn51aa02 secobarbital qn51aa30 combinations of barbiturates qn51aa51 pentobarbital, combinations qn51aa52 secobarbital, combinations qn51ax other products for animal euthanasia qn51aa50 combinations