Meta-analysis Shows Benefit of n-acetylcysteine (NAC)
Dr, Mario Cazzola and colleagues published a review of 13 studies which examined the effects of n-acetylcysteine (abbreviated NAC) in preventing COPD exacerbations. Exacerbations are worsening of COPD symptoms usually shortness of breath and cough typically due to a chest infection (acute bronchitis or pneumonia). The review was published in September 2015 issue of the European Respiratory Review (volume 24; pages 451-461).
What is NAC? It is a antioxidant that is available as a health supplement in the United States, typically in capsule form. Antioxidants are widely used to protect cells from damage induced by reactive oxygen species.
Results: Those with COPD who had chronic bronchitis (coughing up mucus most days) had significantly fewer exacerbations with NAC compared with placebo (inactive). There was a 35% reduction in exacerbations for 635 patients based on four studies at a dose of at least 1,200 mg of NAC each day. The authors states that NAC was well tolerated.
My Comment: This report is called a meta-analysis which means it combines all published studies on a particular topic. Why do this? Many individual studies may not include enough subjects to show a difference in treatment. However, a meta-analysis includes a larger group although the studies are not usually identical in design.
NAC is not a prescription medication. It is typically available at health food stores or can be ordered on line. Based on this meta-analysis, a dose of 600 mg capsules taken twice a day is recommended IF you have the chronic bronchitis type of COPD. Certainly, you should discuss the use of NAC with your health care provider before starting this supplement. There is no evidence that NAC will help those with the emphysema type of COPD.
Dr. Mario Cazzola of the University of Rome Tor Vergata
Example of one product of n-acetylcysteine
NAC is also used to treat an overdose of acetaminiphen (Tylenol) and to loosen thick mucus as can occur in those with cystic fibrosis and COPD.
Another NAC product