Thorax 68:338-343 doi:10.1136/thoraxjnl-2012-202225
  • Chronic obstructive pulmonary disease
  • Original article

Use of nebulised magnesium sulphate as an adjuvant in the treatment of acute exacerbations of COPD in adults: a randomised double-blind placebo-controlled trial

  1. on behalf of the Magnesium COPD Study Team
  1. 1Medical Research Institute of New Zealand, Wellington, New Zealand
  2. 2Capital and Coast District Health Board, Wellington, New Zealand
  3. 3Hutt Valley District Health Board, Lower Hutt, New Zealand
  4. 4Wellington School of Medicine and Health Sciences, Wellington, New Zealand
  1. Correspondence to Dr Philippa Shirtcliffe, Medical Research Institute of New Zealand, P O Box 7902, Wellington 6242, New Zealand; pip.shirtcliffe{at}
  • Received 31 May 2012
  • Revised 21 November 2012
  • Accepted 29 November 2012
  • Published Online First 7 January 2013


Background Intravenous magnesium has been shown to cause bronchodilation in acute severe asthma and in small trials in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). There is also some evidence of benefit from nebulised magnesium in acute severe asthma. Our hypothesis was that adjuvant magnesium treatment administered via repeated nebulisation was effective in the management of AECOPD.

Methods In this randomised double-blind placebo-controlled trial, we approached 161 patients with AECOPD presenting to the emergency departments at two New Zealand hospitals with a forced expiratory volume in 1 s (FEV1) <50% predicted 20 min after initial administration of salbutamol 2.5 mg and ipratropium 500 µg via nebulisation. Patients received 2.5 mg salbutamol mixed with either 2.5 ml isotonic magnesium sulphate (151 mg per dose) or 2.5 ml isotonic saline (placebo) on three occasions at 30 min intervals via nebuliser. The primary outcome measure was FEV1 at 90 min.

Results 116 patients were randomised, 52 of whom were randomly allocated to the magnesium adjuvant group. At 90 min the mean (SD) FEV1 in the magnesium group (N=47) was 0.78 (0.33) l compared with 0.81 (0.30) l in the saline group (N=61) (difference −0.026 l (95% CI −0.15 to 0.095, p=0.67). No patients required non-invasive ventilation. There were 43/48 admissions to hospital in the magnesium group and 56/61 in the saline group (RR 0.98, 95% CI 0.86 to 1.10, p=0.69).

Conclusions Nebulised magnesium as an adjuvant to salbutamol treatment in the setting of AECOPD has no effect on FEV1.

Australian New Zealand Clinical Trials Registry ACTRN12608000167369.