Decreased cortisol response to insulin induced hypoglycaemia in asthmatics treated with inhaled fluticasone propionate

Aims: To assess adrenal function in asthmatic children treated with inhaled fluticasone propionate for up to 16 weeks. Methods: Children with asthma and bronchial hyperresponsiveness to inhaled methacholine were treated with inhaled fluticasone 250-750 μg/day via Volumatic spacer. The insulin tolerance test (ITT) was performed to assess adrenal function. Results: Eighteen asthmatic patients (10 boys, 8 girls), aged 7-17 years received inhaled fluticasone therapy at a median dose of 477 μg/m² per day for 5-16 weeks. Adrenal suppression, defined as 60 minute serum cortisol less than 500 nmol/l, was found in 9 of 18 children. Following the ITT, the median basal and 60 minute serum cortisol concentrations of the suppressed group were 135.0 and 350.0 nmol/l, respectively; the corresponding values for the unsuppressed group were 242.2 and 564.7 nmol/l. Repeat ITT in the suppressed group 2-3 months after discontinuation of fluticasone revealed that all patients had a 60 minute serum cortisol greater than 500 nmol/l. Conclusion: After therapy for asthma with inhaled fluticasone at approximately 500 μg daily for up to 16 weeks, half the children had evidence of adrenal suppression.