Prednisone
"I have had fairly sever asthma all of my life, and prednisone does the trick each time my symptoms become unmanageable with a rescue inhaler.  While the side effects are unpleasant at times, they are not long lasting and worth it to be able to breathe again.  I get irritable, flushed in the face, and a bit bloated.  I have never had to take this more than six days, so this goes away once I finish the medicine."