I added clofazimine about a year after not clearing on azithromycin, ethambutol and rifampin daily. Previously, I was on the 3 antibiotics on the 3x/week schedule for 6 months, and didn't clear. My doctor did not wish to drop any medication (I was on 5 antibiotics for a while) since I clearly had resistant disease and my drug sensitivity tests were still showing activity against MAC for all the drugs. The pill form of clofazimine is available as a compassionate use drug, and I understand there currently are research trials using an inhaled formulation. My ID doctor has had good tx success in adding clofazimine, which is a very low side effect med (I had none, other than a slight "suntanned" appearance) at the dose for MAC, but after 6 months, I was still MAC positive. We then added Arikayce (while maintaining the other 4 antibiotics) which, so far, appears to be successful in getting clear cultures. By the way, the active drug in Arikayce IS amikacin, but the inhaled liposomal formulation has fewer side effects and less toxicity than IV amikacin. After starting Arikayce, my doctor did a peak amikacin blood level and it was well below the level where there would be concerns about toxicity. This is one of the advantages of Arikayce: lower systemic absorption than amikacin because the liposomes attach directly to the lungs. Also, the dose can be adjusted: daily, or 3x/week, or even, according to the specialty pharmacy pharmacists, (always available for patient consults), reducing the dose for each tx from the usual 14-20 minute tx to a shorter time frame.