Naltrexone is a medicine that reduces your desire for alcohol. After you quit drinking, naltrexone may help you stay sober for a long time. This medicine is not a complete cure for alcoholism, but it can help you stop drinking while you get any other treatments that your doctor recommends.Chronic” means that it lasts for a long time or it causes problems again and again. The main treatment for alcoholism is to stop drinking alcohol. This can be difficult, because most people who are alcoholics still feel a strong desire for alcohol even after they stop drinking.