Background: Exercise-induced asthma causes cough, dyspnea, wheeze and chest tightness. Management of focuses on prevention through pharmaco-therapy and alternate strategies. Single use, pre-exercise beta2-agonists and non-steroidal anti-inflammatory agents such as the cromones are the most common treatments.
Objectives: The objective of this review was to assess the effects of a single dose of nedocromil sodium to prevent exercise-induced bronchoconstriction.
Search strategy: We searched the Cochrane Airways Group trials register, the Cochrane Controlled Trials Register, Current Contents, review articles, textbooks and reference lists of articles. We also contacted the drug manufacturer and primary authors for additional citations.
Selection criteria: Randomised trials comparing a single dose of nedocromil sodium with placebo to prevent exercise-induced bronchoconstriction in people over six years of age.
Data collection and analysis: Trial quality assessment and data extraction were conducted independently by two reviewers. Study authors were contacted for confirmation of data.
Main results: Twenty randomised controlled trials involving 280 participants were identified. 15-60 min following inhalation of 4 mg nedocromil, the maximum fall in forced expiratory volume in one second due to exercise was improved by 15.6%, (95% CI:13.2 to 18.1) compared to the placebo response. The maximum percentage fall in peak expiratory flow rate was of the same magnitude (weighted mean difference 15.0%; 95% CI 8.3 to 21.6). Nedocromil shortened the time to recover lung normal function from more than 30 minutes with placebo to less than 10 minutes with the drug. The relative magnitude of its effect was greatest in patients with more severe exercise-induced bronchoconstriction (defined as an exercise-induced fall in lung function > 30% from baseline). There were no significant adverse effects reported.
Reviewer's conclusions: Nedocromil sodium used before exercise appears to reduce the severity and duration of exercise-induced bronchoconstriction. This effect appears to be more pronounced in people with severe exercise-induced bronchoconstriction.