Let's sidestep the primary question of whether addiction is a disease, and ask whether addiction may be cured by medicine.
Can addiction be cured by medicine?
The University of Penn Health system says:
Can Addiction Be Cured?
Can diabetes be cured? No. It can be managed successfully with proper treatment. But treatment is lifelong. It's chronic, it's progressive, it's characterized by relapses…and if untreated or mistreated, it can and will result in death.
Yet, addiction, a similar disease, is supposed to be CURED in 7 days…or 28 days of treatment. It doesn't make sense. There is no cure for any of these chronic, progressive diseases. They all require lifelong treatment. Addiction is no different.
http://www.uphs.upenn.edu/addiction/berman/treatment/
The National Institute on Drug Abuse (USA) says this:
Can addiction be treated successfully?
Yes, addiction is a treatable disorder. Research on the science of addiction and the treatment of substance use disorders has led to the development of research-based methods that help people to stop using drugs and resume productive lives, also known as being in recovery.
Can addiction be cured?
Like other chronic diseases such as heart disease or asthma, treatment for drug addiction usually isn't a cure. But addiction can be managed successfully. Treatment enables people to counteract addiction's disruptive effects on their brain and behavior and regain control of their lives.
https://www.drugabuse.gov/publications/drugs-brains-behavior-science-addiction/treatment-recovery
In an interview with Sally Satel, Scientific American reported:
Is it possible to cure yourself of addiction without professional help? How often does that happen?
Of course it's possible. Most people recover and most people do it on their own. That's in no way saying that everyone should be expected to quit on their own and in no way denies that quitting is a hard thing to do. This is just an empirical fact. It is even possible that those who quit on their own could have quit earlier if they sought professional help. The implicit message isn't that treatment isn't important for many—in fact it should probably be made more accessible—but it is simply a fact that most people cure themselves.
https://www.scientificamerican.com/article/can-you-cure-yourself-of-addiction/