Inhaled magnesium sulfate in the treatment of acute asthma.

BACKGROUND: Asthma exacerbations can be frequent and range in severity from relatively mild to status asthmaticus. The use of magnesium sulfate (MgSO4) is one of numerous treatment options available during acute exacerbations. While the efficacy of intravenous MgSO4 has been demonstrated, little is known about inhaled MgSO4. OBJECTIVES: To examine the efficacy of inhaled MgSO4 in the treatment asthma exacerbations. SEARCH STRATEGY: Randomised controlled trials were identified from the Cochrane Airways Group "Asthma and Wheez*" register. These trials were supplemented with trials found in the reference list of published studies, studies found using extensive electronic search techniques, as well as a review of the gray literature and conference proceedings. SELECTION CRITERIA: Randomised (or pseudo-randomised) controlled trials were eligible for inclusion. Studies were included if patients were treated with nebulised MgSO4 alone or in combination with beta2-agonist and where compared to beta2-agonist alone or inactive control. DATA COLLECTION AND ANALYSIS: Trial selection, data extraction and methodological quality were assessed by two independent reviewers. Efforts were made to collect missing data from authors. Results from fixed effects models are presented as standardized mean differences (SMD) for pulmonary functions and relative risks (RR) for hospital admission; both are displayed with their 95% confidence intervals (95% CI). MAIN RESULTS: Six trials involving 296 patients were included. Four studies compared nebulised MgSO4 with beta2-agonist to beta2-agonist and two studies compared MgSO4 to beta2-agonist alone. Three studies enrolled only adults and 2 enrolled exclusively pediatric patients; three of the studies enrolled severe asthmatics. Overall, there was a non significant improvement in pulmonary function between patients whose treatments included nebulised MgSO4 in addition to beta2-agonist (SMD: 0.23; 95% CI: -0.03 to 0.50; 4 studies). Hospitalizations were similar between the groups (RR: 0.69; 95% CI: 0.42 to 1.12; 3 studies). Subgroup analyses did not demonstrate significant differences in lung function improvement between adults and children, but in severe asthmatics the lung function difference was significant (SMD: 0.55; 95% CI: 0.12 to 0.98). Conclusions regarding treatment with nebulised MgSO4 alone are difficult to draw due to lack of studies in this area. AUTHORS' CONCLUSIONS: Nebulised inhaled magnesium sulfate in addition to beta2-agonist in the treatment of an acute asthma exacerbation, appears to have benefits with respect to improved pulmonary function in patients with severe asthma and there is a trend towards benefit in hospital admission. Heterogeneity between trials included in this review precludes a more definitive conclusion.

Inhaled magnesium sulfate in the treatment of acute asthma.

BACKGROUND: Asthma exacerbations can be frequent and range in severity from relatively mild to status asthmaticus. The use of magnesium sulfate (MgSO4) is one of numerous treatment options available during acute exacerbations. While the efficacy of intravenous MgSO4 has been demonstrated, little is known about inhaled MgSO4. OBJECTIVES: To examine the efficacy of inhaled MgSO4 in the treatment asthma exacerbations. SEARCH STRATEGY: Randomised controlled trials were identified from the Cochrane Airways Group "Asthma and Wheez*" register. These trials were supplemented with trials found in the reference list of published studies, studies found using extensive electronic search techniques, as well as a review of the gray literature and conference proceedings. SELECTION CRITERIA: Randomised (or pseudo-randomised) controlled trials were eligible for inclusion. Studies were included if patients were treated with nebulised MgSO4 alone or in combination with beta(2)-agonist and where compared to beta2-agonist alone or inactive control. DATA COLLECTION AND ANALYSIS: Trial selection, data extraction and methodological quality were assessed by two independent reviewers. Efforts were made to collect missing data from authors. Results from fixed effects models are presented as standardized mean differences (SMD) for pulmonary functions and relative risks (RR) for hospital admission; both are displayed with their 95% confidence intervals (95% CI). MAIN RESULTS: Six trials involving 296 patients were included. Four studies compared nebulised MgSO4 with beta2-agonist to beta2-agonist and two studies compared MgSO4 to beta2-agonist alone. Three studies enrolled only adults and 2 enrolled exclusively pediatric patients; three of the studies enrolled severe asthmatics. Overall, there was a significant difference in pulmonary function between patients whose treatments included nebulised MgSO4 in addition to beta2-agonist (SMD: 0.30; 95% CI: 0.03 to 0.56; 4 studies); however, hospitalizations were similar between the groups (RR: 0.69; 95% CI: 0.42 to 1.12; 3 studies). Subgroup analyses did not demonstrate significant differences in lung function improvement between adults and children, but were significantly different between severe and mild to moderate asthmatics (SMD: 0.69; 95% CI 0.13 to 1.25). Conclusions regarding treatment with nebulised MgSO4 alone are difficult to draw due to lack of studies in this area. AUTHORS' CONCLUSIONS: Nebulised inhaled magnesium sulfate in addition to beta2-agonist in the treatment of an acute asthma exacerbation, appears to have benefits with respect to improved pulmonary function and there is a trend towards benefit in hospital admission. The benefit is significantly greater in more severe asthma exacerbations. Heterogeneity between trials included in this review precludes a more definitive conclusion.

Inhaled magnesium sulfate in the treatment of acute asthma.

BACKGROUND: Asthma exacerbations can be frequent and range in severity from relatively mild to status asthmaticus. The use of magnesium sulfate (MgSO4) is one of numerous treatment options available during acute exacerbations. While the efficacy of intravenous MgSO4 has been demonstrated, little is known about inhaled MgSO4. OBJECTIVES: To examine the efficacy of inhaled MgSO4 in the treatment asthma exacerbations. SEARCH STRATEGY: Randomised controlled trials were identified from the Cochrane Airways Group "Asthma and Wheez*" register. These trials were supplemented with trials found in the reference list of published studies, studies found using extensive electronic search techniques, as well as a review of the gray literature and conference proceedings. SELECTION CRITERIA: Randomised (or pseudo-randomised) controlled trials were eligible for inclusion. Studies were included if patients were treated with nebulised MgSO4 alone or in combination with beta2-agonist and where compared to beta2-agonist alone or inactive control. DATA COLLECTION AND ANALYSIS: Trial selection, data extraction and methodological quality were assessed by two independent reviewers. Efforts were made to collect missing data from authors. Results from fixed effects models are presented as standardized mean differences (SMD) for pulmonary functions and relative risks (RR) for hospital admission; both are displayed with their 95% confidence intervals (95% CI). MAIN RESULTS: Six trials involving 296 patients were included. Four studies compared nebulised MgSO4 with beta2-agonist to beta2-agonist and two studies compared MgSO4 to beta2-agonist alone. Three studies enrolled only adults and 2 enrolled exclusively pediatric patients; three of the studies enrolled severe asthmatics. Overall, there was a significant difference in pulmonary function between patients whose treatments included nebulised MgSO4 in addition to beta2-agonist (SMD: 0.37; 95% CI: 0.1 to 0.63; 4 studies); however, hospitalizations were similar between the groups (RR: 0.64; 95% CI: 0.40 to 1.04; 3 studies). Subgroup analyses did not demonstrate significant differences in lung function improvement between adults and children, or between severe and mild to moderate asthmatics. Conclusions regarding treatment with nebulised MgSO4 alone are difficult to draw due to lack of studies in this area. AUTHORS' CONCLUSIONS: Nebulised inhaled magnesium sulfate in addition to beta2-agonist in the treatment of an acute asthma exacerbation, appears to have benefits with respect to improved pulmonary function and there is a trend towards benefit in hospital admission. Heterogeneity between trials included in this review precludes a more definitive conclusion.

Effect of systemic beta-agonist therapy on IgE production in allergic subjects in vivo.

BACKGROUND: Although beta2-adrenoceptor agonists are widely used in the treatment of asthma, a number of studies have suggested that their long-term use may exacerbate the condition. One possible mechanism for this stems from the in vitro observation that beta2-agonists increase IgE synthesis by human blood mononuclear cells. OBJECTIVE: We sought to examine the effect of regular beta2-agonist therapy on IgE production in vivo in human volunteers. METHODS: Placebo or salbutamol (8 mg BD) tablets were given in a double-blind, randomized fashion to 25 volunteers allergic to grass pollen throughout a period encompassing the UK grass pollen season (April through September). Levels of serum IgE were measured monthly, and nasal IgE was measured at the height and end of the season. Efficacy was assessed through monthly recordings of symptoms of blocked nose (vascular) and other symptoms of rhinitis (nonvascular). RESULTS: For the whole group the geometric mean of serum IgE levels rose from a baseline of 58.7 IU/mL (range, 0 to 1027 IU/mL) to 140 IU/mL (range, 12 to 878 IU/mL) at the height of the pollen season (P =.0001). There was no significant difference between the magnitude of the rise in IgE between the groups with a ratio of increase for salbutamol/placebo of 1.17 (confidence interval = 0.78 to 1.75). There was no change in nasal IgE levels. Total and nonvascular symptom scores were reduced by salbutamol, reaching statistical significance at the height of the pollen season (P <.05). CONCLUSION: An oral dose of the beta2-agonist salbutamol, sufficient to maintain therapeutic levels and provide clinical benefit, does not accentuate the seasonal increase of IgE in human atopic volunteers.