Hey, Jane! Medrol's a medicine called methylprednisolone, a synthetic cortico-steroidal anti-inflammatory that people take for allergic reactions (and other things, too). It's been given to me at times to treat bad asthma attacks. It can definitely enhance or strengthen the effects of other meds, and I'm sure cannabis might be one of them.
http://www.medicinenet.com/methylpre...ne/article.htm