Sodium cromoglycate as a pressurised aerosol (vicrom) in exercise-induced asthma

We investigated the effect of sodium cromoglycate (SCG), delivered as a pressurised aerosol, in a dose of 2 or 4 mg in 15 patients known to have exercise-induced asthma (EIA). All patients had a fall in peak expiratory flow rate (PEFR) greater than 20% of the pre-exercise level following placebo (Range 21.1 to 74.7%). When an identical exercise test was performed after 2 mg of SCG aerosol, nine of the 15 patients had falls in PEFR less than 50% of the value observed on placebo. Of the remaining six patients, four had greater than 50% protection afforded by 4 mg of SCG. Of the 15 patients, 12 had falls in PEFR less than 11% after either 2 or 4 mg of SCG aerosol. The dose of aerosol SCG required to inhibit EIA is only 10 to 20% of that delivered by conventional spinhaler. The apparent superiority of the pressurised aerosol may be due to its site of deposition in the airways.