Lack of efficacy of nebulized magnesium sulfate in treating adult asthma: A meta-analysis of randomized controlled trials.

BACKGROUND: Nebulized magnesium sulfate (MgSO4 ) has been used to treat asthma, but the efficacy remains controversial. We aimed to comprehensively review the efficacy of nebulized MgSO4 in treating adult patients with asthma.

METHODS: PubMed, Embase, and Cochrane Library were searched for relevant studies published up to July 18, 2016. Randomized controlled trials (RCTs) were included if adult patients with acute or stable asthma had been treated with nebulized MgSO4 compared with placebo or another bronchodilator. Standardized mean differences (SMDs), relative risks (RRs) and 95% confidence intervals (CIs) were calculated. Outcomes included pulmonary function, hospital admission and adverse events.

RESULTS: A total of 1386 patients from sixteen trials (1240 acute asthma patients and 146 stable asthma patients) were subjected to meta-analysis. Compared to placebo as normal saline, whether using in acute or stable adult asthma, nebulized MgSO4 did not significantly improve the respiratory function: SMD 0.39 (95% CI -0.03-0.82, P = 0.07), and 1.48 (95% CI -0.14-3.11, P = 0.07), respectively. Furthermore, nebulized MgSO4 did not reduce hospital admission in adult patients with acute asthma (RR, 0.72; 95% CI, 0.52-1.00; P = 0.05), although it was not associated with increased adverse events (RR 1.15; 95% CI, 0.88-1.52; P = 0.31).

CONCLUSIONS: Evidence to date suggests that nebulized MgSO4 has no role in the management of adult patients with acute or stable asthma.