Hi there, I am Dr. Hoellering and pleased to help you. Perhaps ou are refering to Nalmefen (Selincro), which is an anticraving substance not only for alcoholics, but for "critical drinkers" like your grandson as well. It is for "adult patients with alcohol dependence who have a high drinking risk level (DRL) and who do not experience physical withdrawal symptoms and who do not require immediate detoxification". I would ask the GP for this medication. Maybe he didn't know it because it is relatively new on the market. All the best to you and your family!