All I know from experience is that replacing addictions with other substances, drugs whatever you want to call them make you want more of that drug after running out.
Sometimes the cravings will be as bad as alcohol and if you can't get hold of that drug such as codeine, marijuana whatever will make you feel very uncomfortable, not being able to focus, concentrate on anything so first thing this type of person will do is buy a drink from the liquor store.
Source: I'm that type of person.
Staying of all substances is the rule of AA and NA.