Inhaled corticosteroids (ICS) are standard treatment for persistent asthma but it is important to “step down” treatment when possible to minimise adverse effects. The optimal strategy for reducing treatment in mild asthma has not yet been determined.

Five hundred patients with mild asthma (pre-bronchodilator FEV₁ >60% predicted) well controlled on 4–6 weeks fluticasone 100 μg twice daily were included in this randomised, double-blind controlled trial. Subjects were randomised to either continued treatment with fluticasone at the same dose, montelukast 5–10 mg once daily or fluticasone 100 μg once daily and salmeterol (SALM) 50 μg once daily for 16 weeks. The primary outcome measure was time to treatment failure (hospitalisation, systemic corticosteroid use, lung function decline or increased use of rescue treatment). Secondary outcome measures included asthma symptom scores.

Treatment failure was significantly higher in the montelukast group compared with the other two groups (p = 0.03). The commonest reason in all groups for failure was a fall in FEV₁ ⩾20% of the baseline value. Patients treated with montelukast had more frequent nocturnal awakenings than those on fluticasone and worse Asthma Control Questionnaire scores than both groups. However, the montelukast group had fewer upper respiratory infections than both groups and less upper gastrointestinal disturbance than the fluticasone group. The percentage of symptom-free days and other secondary outcome measures were similar in all three groups.

This study provides a rationale for step down in treatment in mild asthma to low dose combined fluticasone–SALM, potentially lowering the mean cumulative ICS dose and adverse effects of ICS. The authors have not discussed the potential effects of the addition of salmeterol and the study does not tell us whether a step down to once daily fluticasone without salmeterol would be effective.