Bronchodilators Don’t Relieve Smoking-Related Symptoms in People Without COPD

NIH researchers have found that dual bronchodilators—long-lasting inhalers that relax the airways and make it easier to breathe—do little to help people who have respiratory symptoms related to smoking but who do not have chronic obstructive pulmonary disease (COPD).

COPD, a lung disease that obstructs the airways and leads to coughing, wheezing and shortness of breath affects about 15 million Americans. However, millions of others who smoke or used to smoke and have some symptoms of COPD have also been prescribed bronchodilators.

“We’ve assumed these medications worked in patients who don’t meet lung function criteria for COPD, but we never checked,” said principal investigator Dr. MeiLan Han, first author of the study. “We now know these existing medications don’t work for these patients.” 

Findings of this NHLBI-funded study, published in the New England Journal of Medicine, underscore the importance of diagnosing lung conditions through spirometry, a lung function test often underutilized in clinical practice. 

Inhalers have long been the primary go-to treatment for these patients. But while smoking causes a large spectrum of lung damage, the study showed bronchodilator therapy only helps patients with enough lung damage that would result in abnormal spirometry readings.

In the 12-week randomized, double-blinded study—part of the Redefining Therapy in Early COPD for the Pulmonary Trials Cooperative—researchers enrolled 535 adults with symptoms of COPD, ages 40-80, at one of 20 U.S. medical centers. Twice daily, study participants used an inhaler that contained either medication or a placebo.

By the end of the trial, some adults in the medication (intervention) and placebo (control) groups saw slight respiratory improvements. However, researchers found no significant differences between those receiving medication or placebo. 

Doctors can help patients who do not meet lung-function criteria of COPD by working with them to address related underlying health issues. 

“In the meantime,” said Han, “research should be focused on finding new treatments for them.”