I am on antibiotics all the time and have been for many years. I started using combos of three about 3 years ago and some combos are better than others, but my doctor likes to add tobi in there as often as possible. There are times ill be on The inhaled tobi ( along with 2 or 3 orals) for just 2 weeks and sometimes im on it a month. It all depends on whats going on with my lungs at the time. Hacing cepacia makes it necessary to be on antibiotics at all times, but using combos makes resistance to one or the other more unlikely, and synergistically they work better.