It should not be a "take it or leave it" drug- ie take when you want, mess around with or play dr yourself about dosage. So many people do this- and I did, too, when I had no intentions of really quitting.
As noted above, a good dr will take into account things like taxation on the liver, etc. Also patient candidacy- my dr is very serious about this and does not prescribe Antabuse to folks not serious about sobriety.
I took it the first 90 days of my sobriety (I am 353 days today) and it was just one of the tools I was putting together in my sober plan. I signed a paper every day and had a witness signature to my taking it - that's how serious we were about me using it correctly. She has some patients come to her office every day for the dose; that wasn't feasible for me so we came up with an alternative plan.
Antabuse- or any other drug- is not a panacea for alcoholism or a ticket to controlled drinking. Taken properly, it is a helpful reminder of what drinking can do to you- KILL YOU- and that's its best use. It was a psychological support for me, as well, as I started my no looking back, never drink again journey to sobriety.
Good luck.