Antabus has a rather strange story. The chemical was used in the production with natural rubber, and people working at these plants got sick when drinking small amounts of alcohol, some doctors noticed this but it was years later it was made to medicine. And they were in reality trying to create medicine against worms. They tested the medicine on them selves and noticed that they could not drink even small amounts of alcohol while on the medicine.
They found that to be a useful side effect and sold the chemical medicine against drinking.