Treatment of severe asthma with intravenous isoproterenol and magnesium

Abstract

In treatment of severely ill asthmatic patients, initial multimodal treatments are inevitable to avoid fatal outcome. We report two severe asthmatic patients who did not respond to inhaled β₂ agonists, but were treated successfully with intravenous isoproterenol and magnesium sulfate. Maximal infusion rate of isoproterenol was 0.16-0.36μg·kg^-1·min^-1, and maximal arterial concentration of ionized magnesium was 0.48-0.83 mmol·l-1. Any signs and symptoms of cardiac ischemia, or muscle weakness were not observed. Magnesium has cardioprotective effects and augments bronchodilation by β₂ agonists in patients with severe, but not mild to moderate, asthma. Intravenous administration of isoproterenol combined with magnesium sulfate would be more effective and safe for the treatment of severe asthma refractory to conventional regimens.