Eleven RCTs (n=4,819), eight of which were double-blind and three single-blind, were included.
Montelukast monotherapy.
Five trials compared montelukast with placebo. Four of these trials found that montelukast was associated with a statistically significant improvement in daytime composite nasal symptom score; the fifth trial had non significant findings for this outcome measure. Three trials also found that loratadine was associated with a statistically significant improvement compared with placebo, and one showed a statistically significant improvement for fluticasone compared with placebo.
Three trials compared montelukast with fluticasone. Two found statistically significant improvements in their primary outcome measures (daytime composite nasal score and hourly nasal symptom score after allergen challenge) in favour of fluticasone; one trial found no significant difference.
Montelukast in combination with antihistamines.
Four trials compared montelukast in combination with loratadine with placebo. The primary outcomes assessed included daytime composite nasal symptom score and average a.m./p.m. peak inspiratory flow. All trials found a statistically significant improvement with montelukast in combination with loratadine compared with placebo. One trial also reported a statistically significant improvement in a.m./p.m. peak inspiratory flow with fexofenadine compared with placebo.
Two trials compared montelukast combined with loratadine with fluticasone. One found no significant difference between the two treatments on daytime composite nasal symptom score. The other found a statistically significant improvement in the RQLQ in favour of fluticasone.
The only trial comparing montelukast combined with loratadine with fexofenadine found no significant difference in average a.m./p.m. peak inspiratory flow.
Two trials comparing montelukast combined with cetirizine with placebo found a statistically significant improvement in favour of the combination in both nasal peak inspiratory flow and composite nasal symptom score. One of these trials also reported a statistically significant improvement with cetirizine alone and cetirizine combined with mometasone compared with placebo for both outcomes. The other trial reported a statistically significant improvement in favour of oral combined with nasal budesonide compared with placebo for both outcomes.