Effects of on-demand β2-agonist inhalation in moderate-to-severe asthma. A randomized controlled trial


Dr Bernd Richter, Heinrich-Heine-Universitaet Duesseldorf, Klinik f. Stoffwechselkrankheiten u. Ernaehrung, Moorenstr. 5, Postfach 101007, D-40001 Duesseldorf, Germany (fax: +49 211 811 8772; e-mail: richterb@uni-duesseldorf.de).


Abstract. Richter B, Bender R, Berger M (Heinrich-Heine-University of Duesseldorf and University of Bielefeld, Germany). Effects of on-demand β2-agonist inhalation in moderate-to-severe asthma. A randomized controlled trial. J Intern Med 2000; 247: 657–666.

Background. The appropriate use of short-acting β2-agonist inhalation in asthma has been the subject of controversy in recent years. Limited information is available for the group of moderate to severe asthmatics with high intake of bronchodilator inhalants and continuous anti-inflammatory protection.

Objective. To investigate the effects of β2-agonist reduction in marked asthma treated with multiple asthma medications.

Design. Randomized, controlled single-blind, cross-over trial.

Setting. Outpatient clinic at a university medical centre.

Subjects. A total of 80 adult patients with moderate-to-severe asthma.

Interventions. In a 1-year study patients were assigned to on-demand vs. regular β2-agonist inhalation treatment.

Main outcome measures. Asthmatic episodes (primary outcome), symptoms, peak expiratory flow rates (PEF) and drug use were recorded daily. Bronchodilator and airway responsiveness, lung function indices and quality of life were assessed during five clinic visits. Also, practicability of β2-agonist tapering in multimedicated asthmatics was analysed.

Results. More than 80% of moderate-to-severe asthmatics were able to reduce their β2-agonist intake by ≥50%. Puffs per day of active therapy decreased from 7.9 in regular to 3.3 in on-demand treated patients (P = 0.0001). The type of β2-agonist used (salbutamol/fenoterol) had no significant impact on the study findings. Almost all parameters of control of asthma improved during the on-demand treatment period.

Conclusion. On-demand inhalation of short-acting β2-agonists in moderate-to-severe asthma is safe, and even in severe asthma a reduction from regular to on-demand β2-agonist inhalation is possible, with improved asthma control.