Introduction

This information paper outlines the current position of leukotriene receptor antagonists (LTRAs) in the treatment of children with asthma.

The leukotrienes are a family of pro-inflammatory mediators that play an important role in the pathophysiology of asthma. Leukotrienes are derived from cell membranes and released following activation of resident airway cells (mast cells) and infiltrating cells (eosinophils and neutrophils). They are involved in both early and late asthmatic airway responses to allergen challenge. Leukotrienes are potent bronchoconstrictors and also cause airway oedema, mucus secretion and recruitment of eosinophils into the airway. Leukotriene receptor antagonists bind to and inhibit specific receptors within the airway.

Montelukast (Singulair) is the only LTRA registered in Australia for use in children aged 2 and older (see Box 1). Montelukast is an orally active, specific LTRA that protects against early- and late-phase bronchoconstriction response to allergen challenge, and against exercise-induced bronchoconstriction.

Box 1. Registered indication and PBS listing (children)

Montelukast sodium (Singulair) is registered for use in children aged 2 years and older for the prophylaxis and treatment of chronic asthma and the symptomatic treatment of seasonal allergic rhinitis. Montelukast is reimbursed by the Pharmaceutical Benefits Scheme. It is available on Streamlined Authority:

  • as a first-line preventer medication in children aged 2–14 years with frequent intermittent asthma or mild persistent asthma as an alternative to sodium cromoglycate or nedocromil sodium (not subsidised for use in combination with other preventer medications).
  • in the prevention of exercise-induced asthma in children aged 6–14 years as an alternative to adding salmeterol xinafoate or eformoterol fumarate, in those whose asthma is otherwise well controlled while receiving optimal-dose inhaled corticosteroid, but who require short-acting beta2 agonist three or more times per week for prevention or relief of residual exercise-related symptoms.