Intravenous magnesium sulfate for asthma exacerbations in children: Systematic review with meta-analysis

BACKGROUND

Asthma is the most prevalent chronic disease in children and constitutes a significant healthcare burden. First-line therapy for acute asthma exacerbations is well established. However, secondary treatments, including intravenous magnesium sulfate (IV-MgSO4), remain variable due to scarcity of data on its efficacy and safety.

OBJECTIVE

To assess the effectiveness and safety of IV-MgSO4 as a second line of treatment in managing children with asthma exacerbations.

METHODS

We searched five databases from inception until April 2023 on randomized clinical trials of IV-MgSO4 in children with acute asthma exacerbations. The primary outcomes were hospitalization rate and length, and change in the severity score. Secondary outcomes included percentage increase in peak expiratory flow rate (PEFR), hospital re-admission rate, need and length for pediatric intensive care unit (PICU) treatment, and adverse effects. Meta-analysis was performed for three outcomes with estimated odds ratios (ORs) or mean differences (MDs) and 95% confidence intervals (CIs).

RESULTS

Eleven studies met the final criteria. In comparison to control, administration of IV-MgSO4 was associated with a reduced hospitalization risk (OR 0.15; 95%CI: 0.03, 0.73) in four studies, and improvement of lung function (MD 26.77% PEFR; 95%CI: 18.41, 54.79) in two studies. There were no significant differences in the length of stay between groups. Due to heterogeneity, a narrative synthesis of other outcomes was performed.

CONCLUSION

The use of IV-MgSO4 demonstrated a reduction in the hospitalization rate and PEFR improvement in children with asthma exacerbations. Adverse effects were rare. Further well-designed studies are needed to better determine the efficacy and safety profile of IV-MgSO4.

Prospective study of serum and ionized magnesium pharmacokinetics in the treatment of children with severe acute asthma

PURPOSE

Intravenous (IV) magnesium sulfate (MgSO₄) is clinically useful as adjunct therapy in treating acute asthma exacerbations. Despite its clinical utility, the disposition of magnesium in children is poorly described. The purpose of this study is to describe the pharmacokinetics (PK) of ionized and total serum magnesium following IV MgSO₄ administration in children with severe acute asthma.

METHODS

Thirty-two children receiving 50 mg/kg IV MgSO₄ for acute asthma exacerbations at Primary Children's Hospital in Salt Lake City, UT, were prospectively enrolled in the study. Blood samples were collected before, as well as 30 min and 2 h after each child's IV MgSO₄ dose, and used to determine total serum and ionized magnesium concentrations. The collected data were analyzed using population PK techniques using NONMEM® software.

RESULTS

Total serum magnesium concentrations were used to externally validate our previously published model constructed with retrospective data (median prediction error 10.3%, median absolute prediction error 18.1%). The mean (%CV) observed endogenous ionized magnesium concentration was calculated to be 6.0 mg/L (12%), approximately one third of the same value for endogenous total serum magnesium (17.6 mg/L (22%)) in this dataset. Weight was a significant predictor of both clearance and volume in a population PK model describing ionized magnesium concentrations. No adverse events were observed in this pediatric cohort.

CONCLUSIONS

This prospective study supports and extends our previous PK analysis of total serum magnesium concentrations. Ionized and total serum magnesium followed similar PK profiles following IV MgSO₄ administration in children. A single bolus infusion of IV MgSO₄ was safe in this small sample of children receiving it for acute asthma.

Clinical pharmacokinetics of magnesium sulfate in the treatment of children with severe acute asthma

PURPOSE

Intravenous (IV) magnesium sulfate (MgSO₄) is used as adjunct therapy to treat acute asthma exacerbations. Despite its clinical use, there is a limited understanding of the disposition of magnesium in children.

METHODS

To explore the pharmacokinetics (PK) of IV MgSO₄ in this population, we collected retrospective data from 54 children who received IV MgSO₄ for treatment of an acute asthma exacerbation at Primary Children's Hospital in Salt Lake City, UT. These data were analyzed using population PK modeling techniques in NONMEM® to determine sources of variability affecting the disposition of magnesium, as well as to predict the dose of IV MgSO₄ needed to achieve clinical benefit.

RESULTS

The covariate analysis found that only weight was a significant predictor of magnesium concentrations in children. Estimated model parameters suggested that magnesium exhibits a short serum half-life (2.7 h) in children. The average endogenous magnesium concentration (prior to administration of IV MgSO₄) was estimated to be 21 mg/L. Simulated data suggested that doses between 50 and 75 mg/kg are required to achieve concentration-time profiles within a hypothesized target therapeutic range between 25 and 40 mg/L.

CONCLUSIONS

These results provide new insight into the disposition of IV MgSO₄ in children and provide dosing guidelines for future prospective studies of IV MgSO₄ in children with acute asthma.