Tachykinin receptors antagonism for asthma: a systematic review

Background: Tachykinins substance P, neurokinin A and neurokinin B seem to account for asthma pathophysiology by mediating neurogenic inflammation and several aspects of lung mechanics. These neuropeptides act mainly by their receptors NK1, NK2 and NK3, respectively which may be targets for new asthma therapy. Methods: This review systematically examines randomized controlled trials evaluating the effect of tachykinins receptors antagonism on asthma. Symptoms, airway inflammation, lung function and airway inflammation were considered as outcomes. We searched the Cochrane Airways Group Specialized Register of Asthma Trials, Cochrane Database of Systematic Reviews, MEDLINE/PubMed and EMBASE. The search is as current as June 2010. Quality rating of included studies followed the Cochrane Collaboration and GRADE Profiler approaches. However, data were not pooled together due to different measures among the studies. Results: Our systematic review showed the potential of NK receptor antagonist to decrease airway responsiveness and to improve lung function. However, effects on airway inflammation and asthma symptoms were poorly or not described. Conclusion: The limited available evidence suggests that tachykinin receptors antagonists may decrease airway responsiveness and improve lung function in patients with asthma. Further large randomized trials are still required.