Antidotes can be divided into three broad catagories: chemical antidotes, pharmacologic antidotes, and functional antidotes. Chemical antidotes act directly on the toxicant to make it less toxic and/or more readily excreted.
Cats are great patients because they are less likely to ingest large amounts of bad stuff just because. However, their unique metabolism presents other challenges as it contributes to the toxicities that we do see in cats and changes, often lowering, the toxic dose we can expect. Also, substances that are safe in other species can be deadly in cats.