Oral magnesium does little in addition to standard treatment for asthma
The use of magnesium supplements as an adjunct to standard asthma treatment in patients with mild-to-moderate disease confers no significant benefits apart from an improvement in forced expiratory volume in 1 second (FEV1) after 8 weeks of treatment, according to the results of a meta-analysis.
Researchers searched multiple online databases for studies trials evaluating the effect of oral magnesium vs placebo or no treatment on disease outcomes in mild and moderate asthmatic patients aged >6 years.
The meta-analysis included eight trials at moderate risk of bias, involving a total of 917 patients. Outcomes included frequency of rescue asthma exacerbation, emergency room visits or hospital admissions, FEV1, forced vital capacity (FVC), peak expiratory flow (PEF), daytime symptoms, daytime activity, night-time symptoms, frequency of bronchodilator use, use of oral or inhaled steroids, side effects, and mortality.
Pooled data revealed that oral magnesium produced an improvement in FEV1 at week 8 (5.69 L/min; 95 percent CI, 1.92–9.46; I2, 45 percent). No other significant improvements in FEV1 were observed at other timepoints.
Furthermore, supplementation did not induce significant changes in FVC, methacholine challenge test, the frequency of bronchodilator use or symptoms score. None of the trials reported on mortality or adverse events.
Overall certainty in estimates was low, and there was some high heterogeneity observed across studies, which was attributed to different type, dose or duration of the intervention across the experimental arms in the included trials.
Based on the results, researchers stressed that oral magnesium cannot be recommended as adjuvants to standard treatment for mild-to-moderate asthma.
In the recent global initiative for asthma guidelines, the use of intravenous magnesium is recommended in acute situations, especially when asthmatics do not respond to initial management. However, the use of oral magnesium for the prevention of asthma exacerbations or to improve control has not been discussed. [West J Med 2000;172:96]