Is it okay to take dextromethorphan while on virtussin ac? for persistent cough, dr gave me virtussin and medrol (methylprednisolone) dose pack.

Usually can do that: Virtussin AC is like Robitussin AC, which is guaifenesin plus codeine. Adding a dose of dextromethorphan (DM) would be like taking the over-the-counter Robitussin DM (guaifenesin and dextromethorphan) plus a bit of prescription codeine. Of course, each patient is different, with various reasons for coughing. That means one should ask his own doctor about what to do when a cough won't go away, or recurs, or worsens.