Antitussive effects of leukotriene receptor antagonists

The leukotriene receptor antagonists represent the newest class of pharmacological agents available for the treatment of asthma. The leukotriene receptor antagonists have been shown in clinical trials to improve asthmatic symptoms, pulmonary function, and bronchial hyperresponsiveness. In a subgroup of asthmatics with cough-variant asthma, cough is the sole or predominant symptom. Initial anecdotal reports suggested that leukotriene receptor antagonists were particularly effective in treating asthmatic cough. A recently published study has confirmed the therapeutic efficacy of zafirlukast in cough-variant asthma, even in patients whose cough had been refractory to inhaled bronchodilators and corticosteroids. The mechanism by which leukotriene receptor antagonists suppress asthmatic cough remains speculative, but may involve inhibition of eosinophilic airway inflammation-induced stimulation of afferent cough receptors. The role of leukotriene receptor antagonists in the chronic treatment of cough-variant asthma awaits definition. Long-term studies evaluating the effect of leukotriene receptor antagonist therapy on chronic airway inflammation and airway remodelling are required.