Little evidence behind bronchodilator therapy for cystic fibrosis

October 25, 2005

Little evidence exists to support the widespread use of bronchodilators to treat children and adults with cystic fibrosis, according to a new systematic review of published research.

"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.

Improvements occurred primarily in a subgroup of the cystic fibrosis patients studied. These patients were known to have bronchial hyper-responsiveness -- increased response of the airway to certain stimuli. Bronchial hyper-responsiveness and responsiveness to bronchodilator drugs are markers for asthma and can be also tested for in people with cystic fibrosis.

The reviewers found the following:

The reviewers found no published trials that included inhaler-delivered fenoterol, formoterol or tiotropium and wrote that use of those agents could not be supported.

The reviewers noted that the trials were too varied in design to allow for a pooling of data for a strict meta-analysis.

"[B]efore embarking on what might become lifelong bronchodilator therapy, bronchodilator responsiveness should be assessed by measuring lung function both before and after a test dose of salbutamol in a standardized way, looking for an increase in baseline FEV1 of at least 10 percent," the reviewers concluded.

John Colombo, M.D., professor and chief of the pediatric pulmonology section at the University of Nebraska Medical Center, said, "My bias is... that all CF [cystic fibrosis] patients deserve a trial of beta-agonist bronchodilator. This should be done in the PFT [pulmonary function test] laboratory, and, unless they develop significant adverse effects, short-acting beta-agonists should be considered as a trial for symptom relief, and possibly as an adjunct to airway clearance. A long-acting beta-agonist, of which salmeterol is the only one studied to date, should be considered for a period of home use with assessment for changes in symptoms, antibiotic requirement, and PFT course."

About 30,000 people in the United States are affected with cystic fibrosis, and 2,500 to 3,000 babies are born annually with the condition. It most commonly occurs in Caucasians of Northern European heredity.
-end-
FOR MORE INFORMATION
Health Behavior News Service: (202) 387-2829 or www.hbns.org.
Interviews: Contact Clare Halfhide at +44 151 228 4811 or chalfhide@hotmail.com

Inhaled bronchodilators for cystic fibrosis (Review). The Cochrane Database of Systematic Reviews 2005, Issue 4.

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Visit http://www.cochrane.org for more information.

By Bruce Sylvester, Contributing Writer
Health Behavior News Service

Center for Advancing Health

Related Cystic Fibrosis Articles from Brightsurf:

Treating cystic fibrosis with mRNA therapy or CRISPR
The potential for treating cystic fibrosis (CF) using mRNA therapies or CRISPR gene editing is possible regardless of the causative mutation.

Cystic fibrosis: why so many respiratory complications?
Cystic fibrosis, one of the most common genetic diseases in Switzerland, causes severe respiratory and digestive disorders.

A newly discovered disease may lead to better treatment of cystic fibrosis
Cystic fibrosis is the most frequent severe inherited disorder worldwide.

New treatment kills off infection that can be deadly to cystic fibrosis patients
The findings, which are published in the journal Scientific Reports, show that scientists from Aston University, Mycobacterial Research Group, combined doses of three antibiotics -- amoxicillin and imipenem-relebactam and found it was 100% effective in killing off the infection which is usually extremely difficult to treat in patients with cystic fibrosis.

Cystic fibrosis carriers are at increased risk for cystic fibrosis-related conditions
A University of Iowa study challenges the conventional wisdom that having just one mutated copy of the cystic fibrosis (CF) gene has no effects on a person's health.

Rare mutations drive cystic fibrosis in Caribbean
Cystic Fibrosis (CF) in the Caribbean is dominated by unusual gene mutations not often observed in previously studied CF populations, according to comprehensive genome sequencing led by physician-scientists at UC San Francisco and Centro de Neumología Pediátrica in San Juan.

Cystic fibrosis carriers at increased risk of digestive symptoms
Researchers have found that carriers of the most common genetic variant that causes cystic fibrosis experience some symptoms similar to those of people with cystic fibrosis.

In cystic fibrosis, lungs feed deadly bacteria
A steady supply of its favorite food helps a deadly bacterium thrive in the lungs of people with cystic fibrosis, according to a new study by Columbia researchers.

Cibio knocks out cystic fibrosis
The fight against cystic fibrosis continues, targeting in particular some of the mutations that cause it.

Hypertonic saline may help babies with cystic fibrosis breathe better
Babies with cystic fibrosis may breathe better by inhaling hypertonic saline, according to a randomized controlled trial conducted in Germany and published in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.

Read More: Cystic Fibrosis News and Cystic Fibrosis Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.