@Fibblet
The problem with both meds is that they only work if they take them faithfully, every day. DB had Antabuse (Disulfiram) and it worked wonders, when he took it. If he decided to go on a bender he simply stopped taking it. Then when he was done, he went back on it. When he finally made up his mind he stayed on it for years and felt it really made a difference. He no longer takes it daily, but does start taking it if he feels himself 'weakening'. This doesn't happen very often. He said the feeling of drinking on Antabuse (tmi follows) is like having the worst case of nausea/motion sickness you can think of but you aren't able to vomit no matter what you try.
Naltrexone wasn't around when he was drinking. It apparently kills the 'buzz' so you drink and don't feel the feelings you're drinking to get. I do know someone who took it and they said it does work, but again, you have to take it faithfully. And with both, it takes time to reach a 'clinical level' in your body where you feel the full effects of drinking, or the full effects of 'no buzz'.
DH has been Rx'd both, not at the same time. But as is usual with him, he expected an immediate 'fix' of the problem. And I guess both meds need time to build up in your system. It was telling to me that the first thing he did after taking a tablet was, wait for it, to drink to 'see if it works'. When it didn't that meant that they don't work at all, despite his own BiL's experiences with Antabuse and his friend's experience with Naltrexone.