Patients with chronic asthma are generally treated with a 'preventer medication' to reduce the underlying airways inflammation but often require bronchodilators for their symptoms. Treatment with regular long acting Beta-agonist bronchodilator agents, such as salmeterol (Serevent) or formoterol (Foradil, Oxis), leads to fewer asthma symptoms during the day and the night, less bronchodilator medication requirement for symptoms, better lung function measurements and better quality of life measurements compared to short acting Beta-agonist bronchodilators such as salbutamol (Ventolin, Asmol, Airomir) or terbutaline (Bricanyl). There were no major adverse effects but there is little information on the effects in patients who do not use a 'preventer medication'.
Long acting inhaled beta-agonists have advantages across a wide range of physiological and clinical outcomes for regular treatment.
Selective beta-adrenergic agonists for use in asthma are: short acting (2 to 6 hours) and long acting (> 12 hours). There has been little controversy about using short acting beta-agonists intermittently, but long acting beta-agonists are used regularly, and their regular use has been controversial.
To determine the benefit or detriment of treatment with regular short- or long acting inhaled beta-agonists in chronic asthma.
We carried out a search using the Cochrane Airways Group trial register. We searched bibliographies of identified RCTs for additional relevant RCTs and contacted authors of identified RCTs for other published and unpublished studies.
All randomised studies of at least two weeks duration, comparing a long acting inhaled beta-agonist given twice daily with any short acting inhaled beta-agonist of equivalent bronchodilator effectiveness given regularly in chronic asthma.
Two reviewers performed data extraction and study quality assessment independently. We contacted authors of studies for missing data.
Thirty one studies met the inclusion criteria, 24 of parallel group and seven cross over design. Salmeterol xinafoate was used as long acting agent in 22 studies and formoterol fumarate in nine.
Salbutamol was the short acting agent used in 27 studies and terbutaline in five. The treatment period was over two weeks in 29 studies, and at least 12 weeks in 20.
25 studies permitted a variety of co-intervention treatments, usually inhaled corticosteroid or cromones. One study did not permit inhaled corticosteroid.
Long acting beta-agonists were significantly better than short acting for a variety of lung function measurements including morning highest forced expiratory flow measured with a peak flow meter (PEF) (Weighted Mean Difference (WMD) 33 L/min 95% CI 25 to 42) or evening PEF (WMD 26 L/min 95% CI 18 to 33); and had significantly lower scores for day and night time asthma symptom scores and percentage of days and nights without symptoms. They were also associated with a significantly lower use of rescue medication both during the day and night. Risk of exacerbations was not different between the two types of agent, but most studies were of short duration which limits the power to test for such differences.