Inhaled corticosteroids for cystic fibrosis
Abstract
Background
Inhaled corticosteroids are increasingly used to treat children and adults with cystic fibrosis (CF). The rationale for this is their potential to reduce lung damage arising from inflammation. It is important to establish the current level of evidence about the potential benefits and harms of this practice, especially in the light of increasing concern about the potential life‐threatening effects of inhaled steroids on adrenal function.
Objectives
To assess the effectiveness of regular inhaled corticosteroids, when compared to no inhaled corticosteroids, in individuals with CF.
Search methods
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We requested information from pharmaceutical companies manufacturing inhaled corticosteroids and authors of identified trials.
Date of most recent search of the Group's Trials Register: February 2006.
Selection criteria
Trials, published and unpublished, comparing inhaled corticosteroids to placebo or standard treatment in individuals with CF. Trials employing randomised or quasi‐randomised methods of treatment allocation were included.
Data collection and analysis
Two independent authors assessed methodological quality of trials using established criteria and extracted data using standard proformas. Differences were resolved by discussion.
Main results
Twenty‐six citations were identified by the searches, of which 21, representing 10 trials were eligible for inclusion. These 10 trials reported the use of inhaled steroids in 293 people with CF aged between 7 years and 55 years. Methodological quality was difficult to assess from published information. Inclusion criteria varied between trials, as did type and duration of treatment and timing of outcome assessments. Objective measures of airway function were reported in most trials but were often incompletely reported or available. Nutritional status, quality of life and survival were not reported in any trial. Only two trials systematically documented adverse effects, and one small trial was halted prematurely when some participants acquired chronic Pseudomonas aeruginosa lung infections.
Authors' conclusions
Evidence from these trials is insufficient to establish if inhaled corticosteroids have a beneficial or harmful effect in people with CF. Further trials are needed to answer these questions. As the practice of prescribing inhaled steroids in CF is already widespread in Europe and increasing in North America, trials to assess whether withdrawing, rather than starting, treatment with inhaled corticosteroids is beneficial or detrimental may be the feasible option.
PICOs
Plain language summary
Not enough evidence to show whether or not inhaled steroids can prevent lung damage in cystic fibrosis
Post‐infection inflammation may contribute to lung damage; long term the most common cause of death in cystic fibrosis (CF). Corticosteroids treat inflammation but may cause adverse effects. These are more severe with oral corticosteroids, but may occur when inhaled regularly in the long term. Some are less serious (oral thrush), others more serious (reduced childhood growth). There is insufficient evidence that inhaled steroids are beneficial in CF or that regular use does no harm. As many centres in Europe and increasingly in North America prescribe these drugs to children and adults with CF, trials of stopping this treatment are needed.
