Acamprosate is used along with counseling and social support to help people who have stopped drinking large amounts of alcohol (alcoholism) to avoid drinking alcohol again. Drinking alcohol for a long time changes the way the brain works. Acamprosate works by helping the brains of people who have drunk large amounts of alcohol to work normally again. Acamprosate does not prevent the withdrawal symptoms that people may experience when they stop drinking alcohol. Acamprosate has not been shown to work in people who have not stopped drinking alcohol or in people who drink large amounts of alcohol and also overuse or abuse other substances such as street drugs or prescription medications.