#ab abusu ad usum

• ab abusu ad usum non valet consequentia — A fundamental principle in bioethics, pharmacovigilance, and clinical toxicology stating that 'a conclusion from the abuse of a thing to its use is not valid'. In medicine, it means that the prohibition or condemnation of a useful drug or medical treatment (e.g., opioids for severe pain) is not justified simply because some patients or individuals abuse it.