Background: Exercise-induced asthma can be prevented by treatment with inhaled furosemide.
Objective: In this study we evaluated the effect and duration of action of two doses (15 and 30 mg) of inhaled furosemide in prevention of exercise-induced asthma in children.
Methods: Ten children with exercise-induced asthma (8 boys and 2 girls, aged 6 to 13 years) were included in the study. Each patient was tested with three treatment regimens (placebo, 15 mg of furosemide, and 30 mg of furosemide) in random order on 3 separate days. Patients performed exercise challenges on a treadmill at 20 minutes and 1, 2, 3, and 6 hours after each treatment. Pulmonary function, urinary output, and fluid intake were monitored.
Results: Both doses of furosemide had a significantly greater protective effect than placebo, but there was no significant difference between the two doses of furosemide. The higher dose of furosemide was associated with increased urinary output and had a longer duration of action.
Conclusion: A 30 mg dose of furosemide is more effective for treatment of exercise-induced asthma in terms of duration but has a significant diuretic effect.