Evidence for the efficacy of montelukast in children with each clinical pattern of asthma is summarised in Appendix 1.

Persistent asthma

• Children with mild persistent asthma should receive regular preventive therapy with LTRAs or low-dose ICS.
• Regular treatment with an ICS is recommended in children with moderate-to-severe persistent asthma.

Large placebo-controlled trials of montelukast once daily in preschoolers and in school-aged children with persistent asthma have demonstrated efficacy on clinical outcomes including increase in proportion of asthma-free days, reduction in daytime and night-time asthma symptoms, and reduction in requirement for short-acting beta2 agonists and oral corticosteroids.^{8, 9} In children old enough to perform spirometry reliably, placebo-controlled trials have also demonstrated efficacy on lung function variables.⁹

The onset of action of montelukast is rapid and sustained, with benefits observed within the first day of treatment.⁸

Montelukast has been shown to improve lung function, night-time wakening and quality of life in children with relatively mild asthma.²² In placebo-controlled studies that included children with moderately severe asthma, montelukast did not reduce exacerbation rates or improve parent-reported measures in pre-schoolers⁸ or reduce night-time wakening due to asthma, symptoms scores or school absences in school-aged children.⁹ Based on data from placebo-controlled trials, it has not been possible to define clinical indicators that predict which children will benefit most from montelukast therapy.²³ In children taking ICS, responses to different add-on therapies differ between individuals.²⁴

In children with mild persistent asthma, montelukast may be an alternative to low-dose ICS for improving clinically relevant measures of asthma control such as short-acting beta2 agonist requirement,¹¹ emergency care visits and hospitalisation rates.²⁵ However, ICS are more effective than montelukast on a range of outcome measures including lung function measures.¹¹ In comparative studies that included children with moderate persistent asthma, ICS were superior to montelukast on clinical, lung function and quality-of-life outcome measures.^26-29

Key findings from clinical trials

• There is substantial evidence that montelukast is an effective preventer therapy, compared with placebo, in children with persistent asthma.
• Comparative studies suggest that the main role for montelukast is as an alternative to low-dose ICS in children with mild persistent asthma or frequent intermittent asthma.
• There is good evidence to support the use of montelukast in children to protect against exerciseinduced bronchoconstriction.
• There is good evidence to support the use of montelukast to manage seasonal allergic rhinitis in children.
• In children with intermittent asthma or viral-induced wheeze, montelukast may help protect against asthma exacerbations associated with respiratory infections, when given either as continual therapy or as short courses in response to the onset of respiratory tract infections.

Intermittent asthma

• Children with infrequent intermittent asthma require treatment only during episodes.
• A short course of montelukast, introduced at the first signs of an asthma episode or upper respiratory tract infection, may reduce symptoms.
• Children with frequent intermittent asthma may benefit from regular preventive therapy with LTRAs or low-dose ICS.

Children with frequent intermittent asthma commonly require preventive treatment only during the winter months. Continuous montelukast once daily may reduce exacerbation rates and ICS requirement in pre-school children with intermittent asthma who have a history of recurrent exacerbations associated with respiratory infections.³⁰ In children with asthma exacerbations associated with respiratory viral infections, the addition of montelukast to usual therapy (including regular ICS for some children) during a predicted season of frequent asthma exacerbations, reduced the duration of asthma symptoms and unplanned visits to doctors.³¹

A short course of montelukast, introduced at the first signs of an asthma episode or upper respiratory tract infection, can achieve a small reduction in symptoms, school absence and medical consultations in preschool and school-aged children with intermittent asthma.³ No comparative studies in children have directly compared the effects of LTRAs, commenced at the onset of exacerbations, with short courses of high-dose ICS. However, a trial comparing low-dose ICS, montelukast and placebo in preschool children with moderate-to-severe intermittent wheezing demonstrated that both ICS and montelukast reduced the severity of symptoms, compared with placebo, but did not reduce the number of event-free days or oral corticosteroid use.³²

Montelukast does not replace oral prednisolone in stabilising asthma after acute episodes requiring emergency department visits.³³

Exercise-induced asthma

Montelukast is an alternative to pre-exercise short-acting beta₂ agonists for exercise-induced asthma prophylaxis.

Treatment with LTRAs lessens, but does not completely prevent, the post-exercise fall in FEV1 that is characteristic of exercise-induced asthma. Like cromones, they enable a more rapid recovery in lung function.³⁴

Continuous montelukast treatment is effective in reducing exercise-induced bronchoconstriction and fall in lung function in children.³⁵ Evidence in an adult population suggests that single-dose montelukast can also be effective when taken the night before or at least 2 hours before exercise.³⁶ Evidence from double-blind, placebo-controlled clinical trials in children with exercise-induced asthma taking ICS suggests that montelukast is more effective than either eformoterol³⁷ or salmeterol³⁸ in protecting against exercise-induced bronchoconstriction.

Montelukast is an alternative to pre-exercise short-acting beta₂ agonist reliever. Frequent use of relievers before exercise should be avoided due to potential receptor tolerance, which may compromise the therapeutic effect when they are required to relieve exercise-related symptoms.³⁹ Long-term montelukast use is not associated with tachyphylaxis, unlike short-acting and long-acting beta₂ agonists.^{38, 39} No attenuation of the bronchoprotective effect was seen after 4 weeks' montelukast treatment in children with asthma and exercise-induced bronchoconstriction in a small (n=32) double-blind randomised clinical trial.⁴⁰

Preventive asthma treatment in children

In a child with persistent asthma, initial therapy options include low-dose ICS or montelukast (Figure 2). If adequate asthma control is not achieved after a trial period of 2-4 weeks with montelukast, it should be replaced with low-dose ICS (Table 1) and the dose titrated as necessary. If asthma control is not achieved using ICS alone, current evidence^24, 41-43 suggests the options include the adding a long-acting beta₂ agonist, adding montelukast, or increasing the ICS dose.

Table 1. Indicative ICS dose equivalents (per day)

*ex actuator dose
**ex valve dose

As with any asthma therapy, commence LTRAs for a trial period of 2-4 weeks then reassess whether the treatment is effective, well tolerated and necessary. Table 2 gives recommendations for commencing or ceasing LTRAs depending on the child's current asthma severity and drug regimen.

Table 2. Starting and stopping LTRA treatment as sole preventer therapyable

Recommendations for starting and stopping LTRA treatment in children with frequent intermittent or mild persistent asthma.

Recommendations apply only to montelukast as the sole preventer therapy. For advice on adding montelukast to a regimen that includes ICS, or in the management of allergic rhinitis, refer to the manufacturer’s Approved Product Information.

Figure 2. Approach to preventive therapy in children