Living with chronic obstructive pulmonary disease? A new class of medications might help you breathe a little easier

The Bottom Line

  • Chronic obstructive pulmonary disease (COPD) reduces the quality of life of many Canadian adults.  
  • A new class of medication called phosphodiesterase 4 (PDE4) inhibitors may improve lung function, reduce the number of bouts of severe breathing difficulty, and improve the quality of life of people with COPD by a small amount.
  • Side effects of using PDE4 inhibitors include: diarrhea, nausea, headache, vomiting, indigestion, and abdominal pain. 

If your life is particularly exciting, it may leave you breathless. Unfortunately, many who experience breathlessness on a regular basis suffer from chronic obstructive pulmonary disease, or COPD.

COPD – a lung disease that blocks air flow to the lungs – affects at least 4% of Canadians, and is a leading cause of illness and death nation-wide (1). In most cases, the symptoms of COPD start to appear after the age of 55, and the severity of the disease increases with age (2).

Symptoms of COPD can include shortness of breath, coughing, wheezing, and the production of mucus. Many people living with COPD find that these symptoms can interfere with basic daily activities; 45% percent of Canadians with COPD feel that they are in poor health, and 33% report that their health has declined within the last year (3).

Cigarette smokers or ex-smokers are most at risk for COPD, but not everyone who gets COPD has smoked cigarettes. Other risk factors include oversensitive airways, genetics, second-hand smoke, and workplace exposure to dust, organic materials, or air pollution (4).

COPD is a serious condition that unfortunately has no cure (4). However, there is a new treatment on the horizon – phosphodiesterase 4 (PDE4) inhibitors – that may help people with COPD catch their breath (5).

What the research tells us

PDE4 inhibitors are a class of medications that open the airways and reduce lung inflammation. Two drugs, which come in tablet form and are taken orally, are currently available: roflumilast and cilomilast.

A recent systematic review found that people with COPD who took PDE4 inhibitors experienced improved lung function. These findings were based on tests that measured the maximum amount of air a person can forcefully exhale in one second. However, it is not clear whether these improvements in lung function translate into detectable benefits for COPD patients. Additionally, research has shown that PDE4 inhibitors produce a small improvement in quality of life. People who took PDE4 inhibitors also experienced fewer episodes of severe breathing difficulty, but did not report improved exercise tolerance.

PDE4 inhibitors were not without side effects. Common side effects included diarrhea, nausea, headache, vomiting, indigestion, and abdominal pain. In fact, over 10% of people taking PDE4 inhibitors experienced these troublesome side effects. People taking roflumilast were particularly prone to weight loss, while high dose roflumilast was associated with an increased risk of negative psychiatric effects.

Although the results are promising, additional research needs to be done to determine the long-term positive and negative effects of PDE4 inhibitors, and whether these new medications can slow the progression of COPD (5). If you have COPD, talk to your doctor about whether PDE4 inhibitors are a good option for you.

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Author Details


  1. Evans J, Chen Y, Camp PG, et al. Estimating the prevalence of COPD in Canada: Reported diagnosis versus measured airflow obstruction. [Internet] 2015. Statistics Canada, Canada. Available from http://www.statcan.gc.ca/pub/82-003-x/2014003/article/11908-eng.htm 
  2. Government of Canada. Chronic obstructive pulmonary disease (COPD). [Internet] 2014. Government of Canada, Canada. Available from https://www.canada.ca/en/public-health/services/chronic-diseases/chronic-respiratory-diseases/chronic-obstructive-pulmonary-disease-copd.html 
  3. Public Health Agency of Canada. Fast facts about Chronic Obstructive Pulmonary Disease (COPD) 2011. [Internet] 2011. Government of Canada, Canada. Available from https://www.canada.ca/en/public-health/services/chronic-diseases/reports-publications/fast-facts-about-chronic-obstructive-pulmonary-disease-copd-2011.html 
  4. Han ML, Stoller JK, Hollingsworth H. Patient education: Chronic obstructive pulmonary disease (COPD), including emphysema (Beyond the Basics). [Internet] 2017. UpToDate, USA. Available from  https://www.uptodate.com/contents/chronic-obstructive-pulmonary-disease-copd-including-emphysema-beyond-the-basics 
  5. Chong J, Leung B, Poole P. Phosphodiesterase 4 inhibitors for chronic obstructive pulmonary disease. Cochrane Database Syst Rev. 2017; 9:CD002309. doi: 10.1002/14651858.CD002309.pub5. 

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