Researchers have found that dual bronchodilators do not help people with respiratory symptoms similar to chronic obstructive pulmonary disease (COPD) and a history of smoking.
COPD is a lung disease that obstructs the airways, leading to coughing, wheezing, and shortness of breath that affects around 1.2 million people in the UK. However, millions of others who smoke or used to smoke and have some symptoms of COPD have 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 MeiLan K Han, MD, a principal investigator and first author of the study. “We now know these existing medications don’t work for these patients.”
The study was funded by the National Heart, Lung, and Blood Institute (NHLBI) and the findings were published in the New England Journal of Medicine and presented at the European Respiratory Society International Congress.
Effective treatment needed for respiratory symptoms
The researchers noted the implications of using bronchodilators for non-COPD conditions. The findings highlight the importance of diagnosing lung conditions using spirometry, an underutilised lung function tool and the need for new therapies for patients without COPD.
Han explained in the study that bronchodilators have long been recommended for these kinds of patients. Doctors assume a patient has COPD, and the smoking-related symptoms could be solved through a bronchodilator. However, whilst smoking can cause significant lung damage, the study revealed that using this therapy only helps patients with enough lung damage that would result in an abnormal spirometry reading.
Studying the effects of bronchodilators
To solidify their findings, the researchers carried out a 12-week, randomised, double-blind study as part of the Redefining Therapy in Early COPD for the Pulmonary Trials Cooperative (RETHINC). The researchers enrolled 535 adults with symptoms of COPD, aged between 40-80, at one of 20 US medical centres. The participants used the bronchodilators twice a day containing either medication or a placebo.
By the end of the trial, some of the adults in the medication group (intervention) and placebo group (control) saw slight improvements, for example, they coughed less, produced less phlegm, or felt less winded, which was assessed using the St. George’s Respiratory Questionnaire. Significantly, the researchers discovered no considerable differences between those receiving medication or placebo. They reported that 56% (128 of 227) of participants who received the medication saw respiratory symptom improvements, compared to 59% (144 of 244) of those taking the placebo.
According to Han, these data underscore why we can’t continue to do what we have been doing, which is not doing spirometry and just treating patients with the same COPD medications and expect that we’re going to see improvement.
Antonello Punturieri, MD, PhD, programme director of NHLBI’s Chronic Obstructive Pulmonary Disease/Environment Program, said spirometry testing should be used for any patient who shows signs of COPD, airflow obstruction, or who has a history of cigarette smoking. Though spirometry readings are used during about one-third of medical visits related to COPD, roughly half of patients who would meet the criteria for COPD go undiagnosed.