Comparable effect of a leukotriene receptor antagonist and long-acting beta₂-adrenergic agonist in cough variant asthma

Abstract

Cough variant asthma (CVA) is a common cause of chronic persistent cough, in which allergic airway inflammation may play a role. Although current guidelines recommend bronchodilators and anti-inflammatory drugs for the treatment, comparison of the efficacy of these medications has not been investigated. This study was designed to evaluate the effectiveness of pranlukast, a leukotriene receptor antagonist, and salmeterol, a long-acting beta₂-adrenergic agonist, in the treatment of CVA. The study was a randomized, controlled, parallel-group, multicenter trial. After a 4-week run-in period, 49 patients with newly diagnosed CVA were assigned to receive oral pranlukast (225 mg, b.i.d.) or inhaled salmeterol (100 μg, b.i.d.) for 4 weeks. Primary outcome measure was cough symptom and secondary outcome measures were pulmonary function and eosinophilic airway inflammation. Treatment with pranlukast and salmeterol each decreased cough symptom scores, where the changes from baseline values were significantly greater in the pranlukast group than in the salmeterol group. Forced expiratory volume in 1 second and peak expiratory flow (PEF) increased in the two treatment groups with the same magnitudes, but significant decreases in diurnal variation of PEF and eosinophil counts and eosinophil cationic protein contents in the peripheral blood and induced sputum were observed only in the pranlukast group. In view of antitussive and anti-inflammatory actions, the leukotriene receptor antagonist pranlukast seems to be more effective than the long-acting beta₂-adrenergic agonist salmeterol in the treatment of CVA.

Effects of regular treatment with combination of salmeterol/fluticasone propionate and salmeterol alone in cough variant asthma

“…In addition, Kim et al [14] found that higher percentage of sputum eosinophils in CVA patients was associated with the development of classic asthma at follow-up, and Fujimura et al [15] reported that treatment with long-term inhaled corticosteroid prevented the development of classic asthma from CVA and reduced bronchial responsiveness. Recently, Tamaoki et al [16] showed that pranlukast, a leukotriene receptor antagonist, caused improvements in cough symptoms and eosinophilic airway inflammation to a greater extent than did salmeterol in patients with CVA. Taken together, anti-inflammatory therapy seems important not only for reduction of cough symptoms but also for prevention of progression to typical asthma in the future.…”

Antitussive Drugs—Past, Present, and Future

“…In a randomized, controlled, parallel-group, multicenter trial of 49 patients with newly diagnosed CVA, the LTRA pranlukast improved cough symptom scores to a greater degree than did the long-acting inhaled b 2 -agonist salmeterol. Furthermore, unlike with salmeterol, a 4-week course of therapy with pranlukast significantly decreased eosinophil counts and eosinophil cationic protein (ECP) contents in peripheral blood and induced sputum (Tamaoki et al, 2010). Three studies have demonstrated the antitussive effect of montelukast (10 mg daily).…”

“…Clinical experience has shown that most patients with CVA will experience improvement in cough after 1 week of b 2 -agonist therapy, although full resolution of cough may require up to 8 weeks of treatment, including an ICS (Irwin et al, 1997). However, the leukotriene receptor antagonists (LTRAs) have been shown to be more effective than b 2 -agonists and ICS asthmatic cough in subjects with asthma (Dicpinigaitis et al, 2002;Tamaoki et al, 2010).…”

Efficacy of procaterol combined with inhaled budesonide for treatment of cough‐variant asthma

“…Clinically, the addition of an elective beta‐2 adrenoceptor agonist has been shown to be more effective than doubling the dose of a steroid inhaler . Although the benefits of beta‐2 adrenoceptor agonists plus steroid inhaler are well established for the treatment of classical asthma, to our knowledge, there are few reports demonstrating the efficacy of these agents in patients with CVA …”