Naltrexone, or Vivitrol, is best known for treating opioid addiction, but it is also used to treat alcohol addiction. It works by blocking blocking mu receptors in the brain so that the endorphins produced by drinking alcohol have no effect. As a result, you still get the impaired speech and motor function but with the glow of intoxication.
Naltrexone has been shown to reduce alcohol use on its own when taken regularly, but it is more effective combined with therapy or used according to the Sinclair Method. The Sinclair Method entails taking a naltrexone pill an hour before drinking. You can drink as much as you want and it won’t have any effect but making you stumble and slur. Eventually, the bottle no longer shines.
The Sinclair Method is based on the principle of extinction. Just as Pavlov’s dogs learned to salivate when they heard the bell, they eventually stopped salivating when the food stopped coming and the bell was only a bell. Similarly, a craving is mainly a conditioned response to some trigger–a smell, a place, a feeling, or whatever–that indicates a reward is coming. When your brain learns that the reward will not follow the trigger, the craving gradually goes away. In this case, the brain learns not to expect a glow from drinking. You don’t get sick like you do with Antabuse, but you don’t get the pleasure either.
It usually takes about three months to extinguish the cravings, but you should still never drink without taking naltrexone because you can learn the old behavior again very quickly.
The crux of this method is taking naltrexone and trying to drink. It’s a bit counterintuitive because treatment for alcoholism typically requires total abstinence. The Sinclair method relies on learning a new response to an old stimulus, which requires repeated exposure to the old stimulus. This is why naltrexone doesn’t extinguish cravings when users don’t drink at all. They still associate the old reward with drinking because they haven’t learned that it doesn’t work anymore.
All of this is to say that naltrexone itself doesn’t magically take away cravings. After detox, you are no longer physically dependent on alcohol. The craving comes from anticipating a reward from drinking. Naltrexone subverts the reward and you gradually unlearn the craving.
The Sinclair Method appears to be an effective form of treatment for people who stick with it, but like any treatment, it requires a real commitment to recovery. If you stop taking the naltrexone because you want to get drunk, then obviously it won’t work. You have to really want to stop. Many people need a barrier more formidable than a pill between them and a serious bender.