Leukotriene antagonists

Montelukast and zafirlukast are available for the treatment of asthma.

• if leukotriene antagonists are used then a short trial (e.g. for 28 days) is advisable to identify those patients who will respond to this therapy class. If there is no evidence of therapeutic benefit after the month trial then the drug should be stopped (1)
• there is evidence to suggest that the leukotriene receptor antagonists, montelukast and zafirlukast, are suitable as add-on treatment in patients with mild or moderate asthma inadequately controlled despite regular conventional doses of inhaled corticosteroid plus 'as needed' inhaled short-acting beta2 agonist (at Step 3 in British guidelines).
  • the average additional clinical benefit however appears slight and, at least in adults, is less than that generally associated with add-on therapy with an inhaled long-acting beta2 agonist (2)
    • thus the guidance is that an inhaled long-acting beta2 agonist should generally be tried first, except in young children (under 4-5 years old), in whom only montelukast is both licensed and known to have efficacy (2)
  • remains unclear whether leukotriene receptor antagonists can enable clinically important tapering of the dose of inhaled corticosteroid, or whether they benefit patients who remain inadequately controlled despite treatment with an appropriate dose of inhaled corticosteroid plus an inhaled long-acting beta2 agonist (i.e. at Step 4 in management) (2)
  • leukotriene receptor antagonists are a potential option for people with exercise-induced bronchoconstriction, but the occurrence of such symptoms may indicate inadequate control of asthma and should prompt a broader review of preventive treatment
  • in patients with poorly controlled asthma, neither montelukast nor low-dose theophylline lowered the episodes of poor asthma control rate of poor asthma control in patients with poorly controlled asthma despite improved lung function (3)

Reference

1. MeReC Bulletin 1999; 1: 1-4.
2. Drug and Therapeutics Bulletin 2005;43(11):85-8.
3. The American Lung Association Asthma Clinical Research Centers. Clinical trial of low-dose theophylline and montelukast in patients with poorly controlled asthma. Am J Respir Crit Care Med. 2007 Feb 1;175(3):235-42.