Using Two versus Three Antibiotics to Treat MAC Lung Infections

Posted on August 26, 2019   |   
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Nontuberculous mycobacterial (NTM) lung disease is caused by serious infections brought on by bacteria that exist in the environment. There are many different types of NTM, but mycobacterium avium complex (also known as ‘MAC’) is the most common. MAC is a type of mycobacteria that is naturally found in soil, water and dust and can affect the lungs, creating shortness of breath, fatigue and cough, to name a few symptoms. MAC is currently treated with a multi-drug regimen, usually 3 or more antibiotics, taken for 18 to 24 months. Side effects of this multidrug regimen may be severe, typically including nausea and diarrhea. As one can imagine, both the disease and its lengthy multidrug treatment can impact patients’ quality of life.

In early 2018, the Patient Centered Outcomes Research Institute (PCORI) approved funding for a “pragmatic clinical trial”, led by Dr. Kevin Winthrop at Oregon Health and Science University (OHSU), that will compare 2-drug therapy versus 3-drug therapy for the treatment of MAC lung disease. Pragmatic trials take place in the setting of “usual care”. The project brings together an important collaboration with patients, patient advocates and clinical stakeholders, including the COPD Foundation and NTM Info & Research.

In this study, 500 adults with the MAC lung infection will be enrolled from 26 sites across the United States and Canada. The team will test and evaluate whether a treatment regimen of 2 drugs is as effective and better tolerated by the patient than a 3-drug regimen. Patients in both treatment groups will receive azithromycin and ethambutol. Group 2 patients will also receive rifampin. Participants are randomly assigned to receive the 2- or 3-drug regimen.

Patients will complete self-reported symptom and quality of life surveys. The research team will also review health records in the first year of treatment to assess the following:

  • status of the MAC infection, 
  • side effects, and
  • issues related to antibiotic resistance 

The 2-drug versus 3-drug comparison in this pragmatic setting may provide much needed data on the common MAC lung treatments and help guide physicians as they create treatment plans for their patients. You can find out more information about the study here.