Drop database does not drop dependent objects

When a debase is dropped, users and roles created in that database are not dropped. Also, those roles are not removed from other roles inheriting from them. When a database with the same name is created (via getDatabase() in the Java driver) these dependent objects show up in the supposedly newly-created database. This is very a confusing semantics. Is there a command to drop dependent objects (e.g., cascade option) when a database is dropped?