Addiction is a disease that generally requires professional treatment. Even if the professional is able to temporarily suppress the symptoms of the disease, remaining well can be a monumental challenge. The underlying causes and issues need to be addressed for long-term health and well-being. The kind of help your friend/co-worker needs requires a great commitment, and crossing those boundaries could jeopardize your current relationship with your friend/co-worker. The best help you can give would be to make the call, then be a strong support to your friend.