It doesn't stop but competes for the metabolic path way, same way that Alcohol stops the body from metabolizing Ethylene Glycol (antifreeze) as it is a competitive binder that the enzyme is better tuned to act upon, so it leave the glycol to be removed by the kidneys.
Funnily enough antifreeze is totally harmless inside the body until the liver gets a hold of it, back in the logging camp we had a couple bottles of 195 proof vodka, it was labeled "Emergency use only" a lot of guys would laugh at that and ask what emergency could there be that alcohol would help. Well, one guy found out, some idiot filled a pop bottle with antifreeze and never labeled it and he drank it thinking it was juice of some sort.
Not precise but ensuring they're drunk till they hit the hospital ensured 100% recovery, other then the head ache from the alcohol, luckily it was discovered fast, thus the very good out come. Luckily this works for dogs too, if you know they drank any amount a dosage of alcohol sufficient to see an observable affect will ensure the glycol is out competed by the ethanol.