Montelukast as add-on therapy to inhaled corticosteroids in the treatment of mild to moderate asthma: a systematic review.

To systematically review the evidence for the medium to long term benefits and risks of montelukast as add-on therapy to inhaled corticosteroids (ICS) in comparison with placebo and active controls in mild to moderate asthma. Medline, Embase, Cochrane Register of Controlled Trials, reference lists of retrieved articles, clinical trial registries and study results databases. Systematic review of randomised controlled trials (duration > or = 12 weeks) in adolescents and adults comparing montelukast/ICS versus ICS monotherapy or montelukast/ICS versus active control/ICS. Meta-analyses were conducted where feasible. The main focus was on clinical outcomes (eg, exacerbations). Adverse events were also assessed. 13 studies meeting all of the inclusion criteria were identified: 7 studies, including constant or tapered doses of ICS, compared montelukast/ICS with ICS monotherapy. Six studies compared add-on montelukast with an add-on active control (salmeterol). Overall, the data indicated that montelukast/ICS was clinically more effective than ICS monotherapy. The ICS sparing potential of montelukast was clearly demonstrated in one study. Montelukast/ICS and ICS monotherapy showed similar safety profiles. In the active controlled studies, montelukast/ICS was clinically less effective than salmeterol/ICS in the 12 week trials (pooled proportion of patients with > or = 1 exacerbation: p = 0.006). However, separate analysis of active controlled 48 week trials showed comparable proportions for patients with > or = 1 exacerbation in both groups. Montelukast as add-on therapy to ICS improves control of mild to moderate asthma compared with ICS monotherapy. Although the addition of salmeterol to ICS is clinically as effective as or even more effective than the addition of montelukast, montelukast may have a better long term safety profile and offer a treatment alternative for asthma patients.