A study published in the New England Journal of Medicine have found that dual bronchodilators do little to help people who do not have chronic obstructive pulmonary disease (COPD), but who do have respiratory symptoms and a history of smoking.
Millions of people 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.”
According to scientists, the implications are significant. First, they show the importance of diagnosing lung conditions through spirometry, a lung function test Dr Han noted is underutilised in clinical practice. Second, they show the need for new, effective therapies for patients without COPD.
Inhalers have long been the primary go-to treatment for these patients, she explained, because doctors either assume a patient has COPD, or else that their smoking-related symptoms could be helped by the inhalers. But while tobacco 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, randomised, double-blinded study, which was part of the Redefining Therapy in Early COPD for the Pulmonary Trials Cooperative (RETHINC), researchers enrolled 535 adults with symptoms of COPD, ages 40–80. Participants used an inhaler twice daily that contained either medication or a placebo.
By the end of the trial, some adults in the medication and placebo groups saw slight respiratory improvements, eg coughed less, produced less phlegm, or felt less winded, which was assessed through the St. George’s Respiratory Questionnaire. However, the researchers found no significant differences between those receiving medication or placebo. They reported 56% (128 of 227) of participants who received the medication saw respiratory symptom improvements, compared to 59% (144 of 244) of those who took the placebo.
According to Dr Han, these data underscore the need to change the standard practice, which is not doing spirometry and just treating patients with the same COPD medications and expecting to see improvement.
Antonello Punturieri, MD, PhD, program 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 criteria for COPD go undiagnosed.
Promoting smoking cessation a primary way to prevent COPD or COPD-like symptoms, the study noted. About one in four current or former smokers without COPD have reported having shortness of breath. In addition to encouraging smoking cessation, doctors can help patients who do not meet lung-function criteria of COPD by working with them to address any other underlying issues, such as overweight and obesity, heart failure, or other lung issues.
“In the meantime, research should be focused on finding new treatments for them,” Dr 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 cough and mucus production show up prominently among these patients, we believe therapies that target mucus production in the airways may be effective,” said Prescott G. Woodruff, MD, a principal investigator and senior author of the study.
Some of these therapies are already in development, and data from other studies may offer insight into the biological causes of excessive airway mucus, which could help point to additional therapies.
