Bronchodilators do not improve smoking-related respiratory symptoms in people without COPD

Press release

Sunday 4 September 2022

Researchers supported by the National Institutes of Health have found that double bronchodilators – long-acting inhalers that relax the airways and make breathing easier – do little to help people who don’t have chronic obstructive pulmonary disease (COPD), but who have symptoms. respirators and a history of smoking.

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

“We hypothesized that these drugs worked in patients who do not meet the lung function criteria for COPD, but we never verified,” said MeiLan K. Han, MD, principal investigator and first author of the study. “We now know that these existing drugs don’t work for these patients.”

The results of the study, funded by the National Heart, Lung, and Blood Institute (NHLBI), were published in the New England Journal of Medicine and presented simultaneously at the International Congress of the European Respiratory Society.

According to the scientists, the implications are significant. First, they show the importance of diagnosing lung conditions through spirometry, a lung function test that Han noted is underutilized in clinical practice. Second, they show the need for new and effective therapies for patients without COPD.

Inhalers have long been the primary go-to treatment for these patients, he explained, because doctors either assume a patient has COPD or, if not, that their smoking-related symptoms could be helped by inhalers. But while tobacco smoke causes a broad spectrum of lung damage, the study showed that bronchodilator therapy only helps patients with sufficient lung damage that would result in abnormal spirometric readings.

In the 12-week randomized double-blind study, which was part of the Redefinition of Early COPD Therapy for Lung Trials Cooperative (RETHINC), researchers enrolled 535 adults with COPD symptoms, aged 40 to 80, in one of 20 US medical centers. Twice a day, study participants used an inhaler that contained either a drug or a placebo.

At the end of the study, some adults in the drug (intervention) and placebo (control) groups experienced mild breathing improvements – this could mean they coughed less, produced less phlegm, or felt less breathless – which was evaluated through St. George’s. Respiratory Questionnaire. However, the researchers found no significant differences between those receiving drugs or placebos. They reported that 56% (128 out of 227) of the participants who received the drug saw improvements in respiratory symptoms, compared with 59% (144 out of 244) of those who took the placebo.

According to Han, this data underscores why we can’t keep doing what we’ve done, which is not doing spirometry and just treating patients with the same COPD medications and expecting that we will see improvements.

Antonello Punturieri, MD, Ph.D., director of NHLBI’s Chronic Obstructive Pulmonary Disease / Environmental Program, said spirometry testing should be used for all patients who show signs of COPD, airflow obstruction, or who have a history of cigarette smoking. Although spirometry readings are used during about one-third of COPD-related doctor visits, about half of patients who would meet the criteria for COPD are not diagnosed.

Helping patients quit smoking is a primary way to prevent COPD or COPD-like symptoms, the study notes. More than 30 million adults smoke, according to the Centers for Disease Control and Prevention, and many who are not diagnosed with COPD share symptoms. About one in four current or previous smokers without COPD reported having dyspnea. In addition to encouraging smoking cessation, doctors can help patients who do not meet COPD lung function criteria by working with them to address any other underlying problems, such as overweight and obesity, heart failure, or other lung problems.

“In the meantime, research should focus on finding new treatments for them,” Han explained. “The next question is, can we develop more targeted therapies for these patients who are on the milder end of the spectrum?”

“Because coughing and mucus production are prominent among these patients, we believe therapies that target mucus production in the airways may be effective,” said Prescott G. Woodruff, MD, principal investigator and senior author. of study.

Some of these therapies are already in development, and data from other studies may offer insight into the biological causes of excess mucus in the airways. These clues could help researchers identify additional therapies.

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To learn about RETHINC and the Lung Testing Cooperative, visit

Information on the National Heart, Lung, and Blood Institute (NHLBI): NHLBI is the global leader in conducting and supporting research into heart, lung and blood disease and sleep disorders that improve scientific knowledge, improve public health and save lives. For more information, visit

Information on the National Institutes of Health (NIH):NIH, the nation’s medical research agency, comprises 27 institutes and centers and is a component of the United States Department of Health and Human Services. NIH is the leading federal agency that conducts and supports basic, clinical and translational medical research and is studying the causes, treatments, and cures for common and rare diseases. For more information on NIH and its programs, visit

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Han MK, Ye W, Wang D, et al. Bronchodilators in symptomatic people exposed to tobacco with preserved spirometry for the RETHINC study group. N English J Med. 2022; doi: 10.1056 / NEJMoa2204752.


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