My mother has MAC lung disease. How often will she need a CT?

Question

Hello doctor,

My mother, aged 61, has MAC lung disease confirmed by sputum culture and HRCT showing nodular bronchiectasis. She has been started on Azithromycin, Ethambutol, and Rifampicin. My concerns are-

How long does this treatment typically last, and when do doctors determine it is safe to discontinue antibiotics?
Are there specific side effects we should monitor with this combination?
Additionally, does airway clearance therapy or steam inhalation aid in removing mucus buildup?
Her latest sputum test still shows some bacterial growth after three months. Does that mean treatment is failing?
How often should follow-up CT scans be done to check lung improvement or damage?

Kindly suggest.

Answer 1

Hello,

Welcome to icliniq.com.

I understand your concern.

Thank you for reaching out about your mother’s condition.

Your mother has MAC (Mycobacterium avium complex) lung disease, which is caused by a slow-growing germ called Mycobacterium avium complex. It needs patience and careful follow-up.

You have already started the right medicines: Azithromycin, Ethambutol, and Rifampicin. The treatment for this infection usually lasts a long time, at least 12 months after her sputum culture becomes negative.

Sputum should be checked every month or two. Once the bacteria are gone and stay gone for a full year, only then is it considered safe to stop antibiotics.

If her sputum is still positive after three months, that is not necessarily a failure; it just means the germ is slow to clear.

We usually see a clear improvement between four to six months. If it stays positive beyond six to nine months, we need to recheck the drug doses or add another medicine to help. Each of the three medicines has a few side effects to watch for:

Azithromycin may cause stomach upset or mild hearing changes.
Ethambutol can affect color vision. So, report any blurring or difficulty seeing red or green immediately.
Rifampicin can turn urine or tears orange and may sometimes affect the liver.

Periodic blood tests and eye check-ups are important. Your mother should have liver function and vision tests every few months. These help to pick up any issues early. Clearing mucus is just as important as taking medicines.

Because MAC thrives in mucus, daily airway-clearance therapy is very helpful. This includes chest physiotherapy, breathing exercises, or devices that make vibrations to loosen phlegm.

Steam inhalation alone is not enough; it helps short-term comfort but not deep mucus clearance. Staying well-hydrated also thins the mucus and makes it easier to cough out.

Follow-up scans, such as HRCT (high-resolution computed tomography), are not needed too often. Usually, one is done at the start and then about once a year unless new symptoms appear, like worsening cough, blood in sputum, or sudden weight loss.

The two main things that guide her improvement are her symptoms and sputum reports.

Hope I have answered all your queries. You may reach out to me for any issue your mother is having. I will be happy to help anytime.

Best wishes.