3.3.2 Leukotriene receptor antagonists

Leukotriene receptor antagonists (LTRAs) alone are less effective than inhaled corticosteroids alone or inhaled corticosteroids (ICS) plus long-acting beta-2 agonists (LABAs) in the management of asthma. Montelukast has not been shown to be more effective than a standard dose of inhaled corticosteroid, but the leukotriene receptor antagonists appear to have an additive effect.
LRTAs may be of benefit in exercise-induced asthma and in those with concomitant rhinitis, but they are less effective in those with severe asthma who are also receiving high doses of other drugs.
If control is still inadequate despite a trial of LABA and increasing ICS dose, then a trial of a LTRA may be considered. It should be stopped after 6 weeks if no improvement.
Montelukast should be taken at bedtime; those patients that experience sleep disturbance will still get a clinical benefit by switching the dose to the morning.

Churg-Strauss syndrome has occurred very rarely in association with the use of leukotriene receptor antagonists; in many of the reported cases the reaction followed the reduction or withdrawal of oral corticosteroid therapy. Prescribers should be alert to the development of eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, or peripheral neuropathy.
Prescribers should be alert for neuropsychiatric reactions in patients taking montelukast and carefully consider the risks and benefits of continuing treatment if they occur – see MHRA.