Sorry I usually only throw up if I've been swallowing a lot of mucus and then have a major coughing attack. My regular regimen is that I do my Xopenex - wait 20 mintues - for it to have maximum airway opening effectiveness. Then do my Hypertonic Saline. Only after my airway clearance is done (huffing etc... I don't have a vest) then I inhale the pulmozyme. The Pulmozyme is pricey and supposedly is effective for more than 12 hours so you don't want to waste it on mucus you're just about to clear out from the Hypertonic Saline. That's why you should do Pulmozyme last. It can work on the next layer of mucus down slowly, over the course of the day helping to break down and thin the thicker mucus. ~Juliet