It’s not used very often anymore because it’s not that effective.
It can be a useful adjunct to other therapy for a highly-motivated patient who is willing to run the risks of consuming alcohol (accidentally or on purpose) while on it, but its success is pretty dismal when court- or employer-mandated for a problem drinker who really doesn’t want to stop.
I remember visiting one county courthouse where the health clinic there dosed alcoholics with their daily liquid dose of antabuse. The steps of the courthouse were discolored yellow where all the clients had spit out the stuff as soon as they got out the door.