My brother in law is living with us and has a very bad addiction problem. He takes anywhere from 15 - 20 750mg Vicodin/Hydrocodone a day. He is only 24 and has been addicted for over a year. I'd really like more information on long term effects from this. Also, the doctors found a mass on his liver about a month ago. Could it be related to his heavy Vicodin usage? Please help!