Use of isotonic nebulised magnesium sulphate as an adjuvant to salbutamol in treatment of severe asthma in adults: randomised placebo-controlled trial

Lancet. 2003 Jun 21;361(9375):2114-7. doi: 10.1016/S0140-6736(03)13721-X.


Background: Intravenous magnesium can cause bronchodilation in treatment of severe asthma, however its effect by the nebulised route is uncertain. We aimed to assess the effectiveness of isotonic magnesium sulphate as an adjuvant to nebulised salbutamol in severe attacks of asthma.

Methods: We enrolled 52 patients with severe exacerbations of asthma presenting to the emergency departments at two hospitals in New Zealand. A severe exacerbation was defined as a forced expiratory volume at 1 s (FEV(1)) of less than 50% predicted 30 min after initial administration of 2.5 mg salbutamol via nebulisation. In this randomised double-blind placebo-controlled trial patients received 2.5 mg nebulised salbutamol mixed with either 2.5 mL isotonic magnesium sulphate or isotonic saline on three occasions at 30 min intervals. The primary outcome measure was FEV(1) at 90 min. Analysis was per protocol.

Findings: At 90 min the mean FEV1 in the magnesium group was 1.96 L (95% CI 1.68-2.24) and in the saline group 1.55 L (1.24-1.87). The difference in the mean FEV(1) between the magnesium and saline groups was 0.37 L (0.13-0.61, p=0.003).

Interpretation: Use of isotonic magnesium as an adjuvant to nebulised salbutamol results in an enhanced bronchodilator response in treatment of severe asthma.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Adolescent
  • Adult
  • Aged
  • Albuterol / administration & dosage*
  • Asthma / drug therapy*
  • Asthma / physiopathology
  • Bronchodilator Agents / administration & dosage*
  • Calcium Channel Blockers / administration & dosage*
  • Chemotherapy, Adjuvant
  • Female
  • Forced Expiratory Volume
  • Humans
  • Magnesium Sulfate / administration & dosage*
  • Male
  • Middle Aged
  • Nebulizers and Vaporizers


  • Bronchodilator Agents
  • Calcium Channel Blockers
  • Magnesium Sulfate
  • Albuterol