DS's prescription for duoneb reads 4 times a day. When he was first diagnosed shortly after his birth, we did CPT 4-5 times a day, especially after he developed bronchitis at 3 months.
His doctor has told us if DS develops a cough or wheeze to "beat it out of him". So if he's feeling under the weather, we'll throw in another cpt/vest treatment, increase the time we do the treatment -- we usually do 3 a day -- 6 a.m., 5:30 p.m. and 10 p.m. -- so we'll add one around noon or middle of the night. We were told to maintain a 4 hour separation between the bronchiodialators. Oh and when DS did have bronchitis and we were doing the extra treatments, I'd also give him some mini-CPT treatments. When I was holding him, I'd give him a few minutes of CPT, sometimes during church... It seemed to calm him and sometimes he'd fall asleep.