Introduction: Magnesium sulfate is not recommended as a routine drug used in acute asthma exacerbations. However in some circumstances of a severe asthma attack a single intravenous dose of magnesium sulfate is purposeful and recommended by Global Initiative for Asthma (GINA, evidence category A). A few randomized, placebo-controled, double-blind clinical trials conducted in some clinical centres worldwide showed ambiguous results. In those trials patients were given infusions of magnesium sulfate in doses not exceeded 2 g. This procedure was safe for patients, with no risk of severe complications.  It seems that increase in a single dose of magnesium to 6 g could improve efficacy of the drug.

The aim of this investigation was to evaluate the  influence of bigger magnesium dose in addition to standard  therapy on the acute asthma therapy outcome according to the clinical, spirometric and gasometric assessment as well as estimation of drugs doses reduction used  in the standard therapy only (without magnesium).

Matherial and methods: A prospective, randomized , placebo-controled, double blind clinical trial was conducted in the Department of Internal Medicine, Geriatry and Allergology. Patients with acute asthma exacerbations who completed the inclusion criteria were included in the study. Patients were divided into two groups and were administered a 270 minutes intravenous infusion of 6g of magnesium sulfate or placebo (normal saline) respectively. The treatment of asthma exacerbation was due to GINA recommendations.

Results: 13 patients with acute asthma exacerbations were included in the study. 6 patients were administered intravenous infusion of 6g of magnesium sulfate and 7 patients – infusion of normal saline as the therapy added to the standard treatment of asthma according to GINA recommendations. Primary end points were duration time to FEV1 >60% predicted or personal best, which lasted more than 4 hours, increase in FEV1 and PEF rate, decrease in tachycardia and tachypnoe and evaluation of dyspnoe (Borg scale) in 270 minute from the beginning of the Mg/placebo treatment, salbutamol and ipratropium bromide used as rescue medications. There were no statistical important differences between the two compared groups.

Conclusions: There were no benefits in application a bigger dose of magnesium sulfate in treatment of acute asthma exacerbations in this study.