Are long-term MAC treatments safe for elderly people?

Question

Hello doctor,

My 68-year-old father was recently diagnosed with a MAC (Mycobacterium avium complex) lung infection after his CT chest showed nodular bronchiectasis. His sputum culture also confirmed MAC infection. The pulmonologist has advised a long-term treatment plan with antibiotics such as Azithromycin and Ethambutol.

We are concerned because he may need to take these medicines for more than a year, and we are worried about the possible side effects.

I have a few questions:

How effective is this long-term antibiotic therapy in clearing MAC infection?
How often should follow-up tests - like CT chest and sputum cultures - be repeated to monitor his response?
Is there a high chance of relapse even after complete treatment?

Please help.

Thank you.

Answer 1

Hi,

Welcome to icliniq.com.

I read your query and can understand your concern.

I completely understand why you feel anxious when you hear that your father needs long-term antibiotics. At his age, anyone would worry. You are doing the right thing by clarifying everything.

The positive news is that the treatment recommended for him is the standard, evidence-based treatment for MAC lung disease.

MAC stands for Mycobacterium avium complex - a slow-growing group of bacteria that can infect the lungs. He also has nodular bronchiectasis, which means the airways in the lungs are widened and damaged, making it easier for infections to stay and return.

For this condition, doctors usually prescribe a combination of antibiotics because one medicine alone is not strong enough to control MAC.

Most common medicines include:

Macrolide antibiotic (like Azithromycin) - Helps kill the MAC bacteria.
Ethambutol - Prevents bacteria from becoming resistant to treatment.
Sometimes a third drug is added for extra support.

When the bacteria are sensitive to the antibiotics and the medicines are taken regularly, many patients show good improvement in cough, breathlessness, and sputum (phlegm).

The goal is to continue antibiotics for at least 12 months after the sputum tests first turn negative. This long treatment duration is important because it allows enough time to fully suppress the bacteria and greatly reduce the chance of the infection returning.

Doctors mainly monitor two things:

Symptoms - Cough, sputum, fever, fatigue, and breathing.
Sputum culture tests - Done every one to three months to check if bacteria are still present.

A CT scan (computed tomography scan - a detailed X-ray of the lungs) is not done frequently because:

Lung changes take time to improve, so frequent scans do not show helpful new information.
Each scan exposes the body to radiation.

A CT is usually repeated only when:

Enough time has passed to assess major progress.
He suddenly becomes worse.

Regarding relapse:

Relapse can happen in MAC, especially in people who have bronchiectasis.
But it is not guaranteed.
Many patients complete the full course and stay stable for years.
If it does return, it does not mean treatment “failed forever.”
It simply means that the lungs are naturally vulnerable and may need another carefully controlled treatment later.

What will help your father the most

Take medicines exactly as prescribed.
Regular follow-ups with the same pulmonologist.
Routine sputum tests.
Report any new side effects quickly. Especially vision changes, because Ethambutol can sometimes affect eyesight

With proper monitoring, many families get through this long treatment safely, and patients notice better cough control, less sputum, more energy, and improved breathing over time.

You are supporting him beautifully by staying informed.

I hope this helps.

Kindly revert so I can assist you further.

Thank you.