Effect of MgSO₄ on FEV₁ in stable severe asthma patients with chronic airflow limitation.
BACKGROUND
The bronchodilating potency of magnesium sulphate (MgSO₄) has been shown in acute asthma exacerbations. We hypothesized that smooth muscle cell relaxation by magnesium might also be beneficial in chronic severe asthma with persistent airflow limitation.


OBJECTIVE
To investigate whether nebulised magnesium, administered according to a dosing scheme shown to be effective in acute asthma, induces bronchodilation in stable asthma patients with persistent airflow limitation.


METHODS
In a placebo-controlled, cross-over study, 13 severe asthma patients with postbronchodilator FEV₁ < 75% predicted received either 2.5 mL MgSO₄ 6.4% or placebo in 3 nebulisations at 30 minute intervals. Before the first and 30 minutes after the last inhalation FEV₁, exhaled nitric oxide (NO) in dyspnoea (Borg) were measured.


RESULTS
After MgSO₄ treatment no improvement in FEV₁ occurred (56.2 ± 16.8 to 55.4 ± 17.4% predicted [p = 0.5]), neither was a change in exhaled NO or Borg observed (p > 0.1). The changes in FEV₁, NO or Borg were not different between the treatment arms (p ≥ 0.09).


CONCLUSIONS
Short-term treatment with magnesium inhalations had no direct bronchodilating effect in stable severe asthma patients with persistent airflow limitation. Yet, clinical observations suggest a heterogeneity in response, probably related to treatment intensity, and support further exploration of magnesium administration in these patients.
Department of Pulmonary Diseases, Medical Centre Leeuwarden, Henri Dunantweg 2, Leeuwarden, The Netherlands.
Alinda M G
AM
Zandsteeg
Petra
P
Hirmann
Henk R
HR
Pasma
Jan-Peter
JP
Yska
Anneke
A
ten Brinke
D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008274:Magnesium / Q000627:therapeutic use*; D008278:Magnesium Sulfate / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged
D008278:Magnesium Sulfate; D008274:Magnesium