"Recurrent wheeze and breathlessness are common in people with cystic fibrosis, and bronchodilators are commonly prescribed," according to lead author Clare Halfhide, M.D., of the Royal Liverpool Children's Hospital in England. "Despite their wide-scale and often long-term use, there is limited objective evidence about their efficacy in cystic fibrosis."
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
Cystic fibrosis is a genetically inherited disease afflicting the lungs and the digestive system, the result of both parents passing on an abnormal gene. It is chronic, progressive and ultimately fatal.
Cystic fibrosis causes the exocrine glands, which produce sweat and mucus, to produce thick mucus that clogs the lungs, causing chronic respiratory difficulties. The mucus also obstructs pancreatic ducts, preventing digestive enzymes from reaching the intestines. Consequently, people with cystic fibrosis have difficulties breathing, absorbing nutrients and eliminating non-digested food.
The Cochrane review included 14 trials randomized controlled trials comprising 257 participants with cystic fibrosis.
Several trials compared inhaled bronchodilator drugs to placebo by looking at two common measures of lung function. Forced expiratory volume, or FEV1, represents the volume of air that can be forced out in one second after taking a deep breath. Peak expiratory flow rate represents how fast a person can exhale air.