I had no instruction from anyone on which one to use (when, where, or how often). I learned a lesson the hard way when it comes to BREO Eppital. All of the other inhalers I could feel either a mist or a powder. With BREO, I felt absolutely nothing so I kept recharging and after 7 attempts of deep inhalation, I finally gave up. Within 2 hours I was certain I was having a heart attack - my chest felt like an elephant was sitting on it. I knew instantly that I had ingested too much of BREO - even though I felt nothing. It has been 4 days since the incident and I can barely function. No, I didn't call for rescue, I suffered through 2 severe attacks and it is beginning to ease up. Next time, I will ask questions before I take anything I'm not sure of. But, why am I on so many inhalers? As for the BREO, I now know the limit is ONE inhalation per day (equals 200 mcg?) This fool took about 7 deep puffs which equals 1400 mcg)