A randomized clinical trial of nebulized magnesium sulfate in addition to albuterol in the treatment of acute mild-to-moderate asthma exacerbations in adults.

STUDY OBJECTIVE: We sought to compare the efficacy and safety of nebulized magnesium sulfate (MgSO(4)) plus albuterol with that of albuterol alone in adult patients with mild-to-moderate acute asthma exacerbations.

METHODS: Patients were randomized to receive nebulized MgSO(4) (384 mg in 6 mL of sterile water) or an equal volume of placebo (normal saline solution) in a double-blind fashion after each dose of nebulized albuterol administered (2.5 mg/3 mL) every 20 minutes for the first hour of the study. Spirometry was performed at baseline and every 20 minutes for 2 hours. Monitoring for safety included vital signs, pulse oximetry, and serum magnesium levels. Improvement in percent predicted forced expiratory volume in 1 second was chosen as a primary efficacy end point.

RESULTS: Among 74 patients enrolled, 37 were randomized to each of 2 study groups. There were no statistically or clinically significant differences between the 2 study groups in percent predicted forced expiratory volume in 1 second at any point during the trial or overall. There were no significant differences in vital signs, pulse oximetry, or serum magnesium levels at any point during the study.

CONCLUSION: The combination of nebulized MgSO(4) and albuterol provides no benefit in addition to that provided by therapy with albuterol in adult patients with mild-to-moderate asthma exacerbations. The efficacy of nebulized MgSO(4) in patients with severe asthma exacerbations remains unknown.