WELLINGTON, NEW ZEALAND. Asthma is an increasingly common disease especially among children. The disorder is allergic in nature and manifests itself as spasms of the airway tubes leading to often-severe difficulties in breathing. The severity of an asthma attack is determined by measuring the forced expiratory volume in one second (FEV1) and comparing it to the normal FEV1. An FEV1 of 50% or less of normal is a severe attack while a FEV1 of 30% or less is life-threatening.
A magnesium deficiency has been implicated in chronic asthma and intravenous injections have been found useful in alleviating severe attacks. Researchers at the University of Otago now report that a combination of the asthma drug salbutamol and an isotonic magnesium solution applied as a spray (nebulized) is highly effective in helping asthma patients recover from an attack. Their clinical trial involved patients who had come to the emergency department because of a severe asthma attack. Upon admission all patients were given 100 mg hydrocortisone intravenously as well as 2.5 mg of salbutamol applied by jet nebulization. At least 30 minutes later the FEV1 of the patients was measured and if it was less than 50% of normal they were randomized to either the magnesium group (28 patients) or the placebo group (24 patients). The placebo group received 3 nebulized doses of 2.5 mg of salbutamol plus saline solution spaced 30 minutes apart before their FEV1 was measured again. The magnesium group received similar treatment except that their nebulizer solution contained 150 mg of magnesium sulphate as well as the 2.5 mg of salbutamol in an isotonic solution.
At 90 minutes the average FEV1 of the magnesium group was 1.96 L as compared to 1.55 L in the placebo
group or 51.2% and 41.3% of normal capacity respectively. Twelve of the patients in the magnesium group
(43%) were admitted to hospital after the trial as compared to 17 in the placebo group (71%). The beneficial
effect of the magnesium was found to be greater in patients with life-threatening asthma (FEV1 less than
30%). The researchers conclude that adding magnesium to the salbutamol solution normally used in the
treatment of asthma greatly enhances its effect, especially in severe and life-threatening attacks.