I Have Severe Asthma And Suffer A Great Deal. I

I have severe asthma and suffer a great deal. I stumbled on vyvanse a couple of years ago and immediately noticed that while on it my breathing improved a great deal. When it wore off my asthma symptoms would come back with a vengeance. I would like my Dr to prescribe vyvanse as a regular treatment for my asthma, as well as other benefits I discovered. How do I go about having a discussion with my Dr to prescribe vyvanse even though there isn't much research about it?