Inhaled glucocorticoids versus leukotriene receptor antagonists as single agent asthma treatment: systematic review of current evidence.

OBJECTIVE To compare the safety and efficacy of anti-leukotrienes and inhaled glucocorticoids as monotherapy in people with asthma. DESIGN Systematic review of randomised controlled trials comparing anti-leukotrienes with inhaled glucocorticoids for 28 days or more in children and adults. MAIN OUTCOME MEASURE Rate of exacerbations that required treatment with systemic glucocorticoids. RESULTS 13 trials (12 in adults, one in children) met the inclusion criteria; all were in people with mild and moderate asthma. Leukotriene receptor antagonists were compared with inhaled glucocorticoids at a daily dose equivalent to 400-450 microg beclometasone dipropionate. Patients treated with leukotriene receptor antagonists were 60% more likely to suffer an exacerbation requiring systemic glucocorticoids (relative risk 1.6, 95% confidence interval 1.2 to 2.2; number needed to treat 27, 13 to 81). A 130 ml greater improvement (80 ml to 170 ml) in forced expiratory volume in one second and a 19 l/min greater increase (14 l to 24 l) in morning peak expiratory flow rate were noted in favour of inhaled glucocorticoids. Differences in favour of inhaled glucocorticoids were also observed for nocturnal awakenings, use of rescue beta2 agonists, and days without symptoms. Risk of side effects was no different between groups, but leukotriene receptor antagonists were associated a 2.5-fold increase risk of withdrawals due to poor asthma control (relative risk 2.5, 1.8 to 3.5). CONCLUSIONS Inhaled glucocorticoids doses equivalent to 400 microg/day beclometasone are more effective than leukotriene receptor antagonists in the treatment of adults with mild or moderate asthma. There is insufficient evidence to conclude on the efficacy of anti-leukotrienes in children.