Yeah I was on TOBI forever then could not get through my off months so I started Colistin on off months and all was good but then my TOBI months were not so great. So started Cayston when it came out with alternating Coli. Cayston was great at first and then about a year later or really 6 months or so of being on it cause it is every other month, I got increased coughing while on Cayston. So NOW I am back to the Tobra/Coli combo..... Ugh, what a game figuring things out......<br>