I just wanted to add this: I did SR, AA, intensive outpatient program, and psychotherapy. They all helped to varying degrees. I guess I'm a "hard case"! After IOP I stayed completely sober for almost 9 months. I relapsed when my PTSD kicked in badly. My doc at that time suggested naltrexone. It helped though I had to experiment with different brands to maximize the effect. With my doc's ok, I took it for a week and then switched to taking it on a PRN basis - meaning one hour before I had a glass of wine. Unorthodox and I definitely don't recommend doing this without your doc's ok and monitoring. What that did for me (once I switched to an uncoated version in blister packs) was to block the action on the opioid receptors. This was only a very short term solution for me. As mentioned above, a determined alcoholic can simply stop taking it!
So I went for several weeks with one glass of wine per week. Sounds good? Well, yes and no. It still took some effort to completely stop. IMHO, it didn't eliminate the need for any of the other things I have done. As a matter of fact, I don't think it would have worked alone to get me where I am today. What it did do was to make me realize deep down that the buzz we think get from alcohol is an illusion.
I needed the peace of mind of knowing that when my PTSD kicks in that I have an relatively easy way to boost my ability to stay sober. For me this was definitely not a way to aim to drink moderately or to use to stay sober without the work. All of the work I have done was still necessary for me. I think of the naltrexone as a bit of a boost for uncommon situations.
Also as noted above, IMHO every drug has unintended side effects. Naltrexone has its share. It is critical to either have a medic-alert bracelet or pendant or at the very least a wallet card stating that you are taking naltrexone.
Please see your doctor if you are considering this, be aware of all of the issues and use all of the non-drug resources available. IMHO it takes changing attitudes and behaviors to stay sober and have a better life.