Inhaled magnesium sulphate in the treatment of bronchial hyperresponsiveness

Magnesium sulphate (MgSO(4)) is one of numerous treatment options available during acute asthma exacerbation. A significant, bronchodilating effect of intravenous MgSO(4) has been demonstrated in previous studies, but its inhaled use is less well-defined.

To investigate the effects of inhaled MgSO(4) alone and in association with a β(2-)agonist in the treatment of bronchial hyperresponsiveness. Methods. We conducted a placebo-controlled, double-blind clinical trial with seventy six adult patients with bronchial hyperresponsiveness. Subjects were randomized into four groups receiving four inhaled products at the end of methacholine (Mech) challenge: NaCl 0.9%, MgSO(4)alone, β(2-)agonist alone, and the combination of MgSO(4)+ β(2-)agonist. Repeated measures of the forced expiratory volume at 1s (FEV(1)) were performed at 0, 5, 10, and 20 minutes after the end of the inhalations. In the MgSO(4)and MgSO(4)+ β(2-)agonist groups, a blood sample was taken before and after inhalation to determine serum magnesium levels. Results. (1) Inhaled MgSO(4) led to a significant improvement of the FEV(1) from the 15(th) minute after its inhalation. (2) β(2-)agonist significantly increased FEV(1) from the 5(th)minute (3) inhaled MgSO(4) + β(2-)agonist led to a significantly greater FEV(1) from the 5(th)minute than inhaled MgSO(4)alone or inhaled β(2-)agonist alone (p<0.05) (4) There is a correlation between low serum magnesium level and the increase in FEV(1)after inhalation of MgSO(4) + β(2-)agonist (p<0.001). Conclusion Inhaled MgSO(4), in combination with β(2-)agonist, appears to have benefits in the treatment of bronchial hyperresponsiveness, especially when associated with hypomagnesemia.