Has the doctor recommended daily airway clearance using saline solution in a nebulizer to help your Mom get the mucus out of her lungs? That is where the bacteria hides, and some people can clear out, or at least knock down the infection that way.

@maureengdds for refractory MAC, which it sounds like your mother has, there is a fourth inhaled antibiotic Arikayce. Arikayce is an inhaled form of amikacin, which is more commonly given for severe MAC disease by IV. Is your mom’s doctor an NTM specialist? It doesn’t sound like it as there are other drugs than the Big 3. I don’t know your mother’s age and overall health profile so this may not be feasible but as you say you are looking for a “Hail Mary” my suggestion would be to seek out an NTM specialist and see if they can come up with a drug regimen that is more tolerable for your mom. It can often take time to get into see an NTM specialist but if you describe your circumstances perhaps they can get your mom in on an expedited basis. If you let us know your general geographical location we can let you know if we know of an NTM expert near(ish) you.