I have been on the 28 days on/28 days off Tobi regimen for many years now. It seems to be effective, but lately I've been having problems during the off-Tobi weeks. I experience a very noticeable decline in lung capacity over that time. I lose tons of sleep because I cough incessantly when my body is horizontal. This is a huge handicap since I'm a full-time student and barely have enough time to sleep between classes, homework, exercising, and doing treatments. By the end of the cycle, I can barely climb the stairs in our apartment without getting completely winded, but within 4 or 5 days of resuming the Tobi, I am back to my normal, albeit limited, lung capacity. Does anyone else have this problem? What do you do to remain functional during those off-weeks?