Rapid effects of inhaled corticosteroids in acute asthma: an evidence-based evaluation

Current reviews on the use of inhaled corticosteroids (ICS) for acute asthma underestimated their early (minutes) clinical impact and produced conclusions of questionable validity.

The analysis of the best evidence available on the early (1 to 4 h) clinical impact of ICS for patients with acute asthma in the emergency department (ED) setting.

Published (from 1966 to 2006) randomized controlled trials were retrieved using different databases (MEDLINE, EMBASE, Cochrane Controlled Trials Register), bibliographic reviews of primary research, review articles, and citations from texts. Primary outcome measures were admission and ED discharge rates.

Seventeen studies met criteria for inclusion in the review (470 adults and 663 children and adolescents). After 2 to 4 h of protocol, a greater reduction in admission rate was observed with trials that used multiple doses of ICS (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.16 to 0.55), especially when they were compared with placebo. Patients treated with ICS also displayed a faster clinical improvement compared with placebo or systemic corticosteroids (SCS), increasing the probability of an early ED discharge (OR, 4.70; 95% CI, 2.97 to 7.42; p = 0.0001). The advantage of the use of ICS was also demonstrated in spirometric and clinical measures as early as 60 min. These benefits were obtained only when patients received multiple doses of ICS along with beta-agonists compared with placebo or SCS.

Data suggests that ICS present early beneficial effects (1 to 2 h) when they were used in multiple doses administered in time intervals < or = 30 min over 90 to 120 min. The nongenomic effect is a possible candidate by covering the link between molecular pathways and the clinical effects of corticosteroids.