@raney Hi Raney,
To answer your question, I do not know of any contraindications of NAC with Asthma. Sorry. I will google and see if anything comes up. I am to be fitted with a Smart Vest shortly and read above that you are using it. Do you find it helpful? Do you use it twice a day? I have bronchiectasis, MAC and just diagnosed with pseudomonas. So my new Pulmo Doctor suggested the vest. I am anxious to get it which should be soon as I have been coughing a lot at night since I got sick in Jan of 2022. I'm guessing that is when I picked up Pseudomonas. Prior to that time it was pretty much easy sailing with just nebulizing 7% saline, NAC and excercise. I hope you are doing well. If I come up with any info on NAC and asthma, I will certainly post . Take good care, Raney.
Kate