Adrenal function as assessed by low-dose adrenocorticotropin hormone test before and after switching from inhaled beclomethasone dipropionate to inhaled fluticasone propionate.

Low-dose adrenocorticotropin hormone (ACTH) tests (0.5 microg/L 73 m2) were done before and after switching from inhaled beclomethasone dipropionate to inhaled fluticasone propionate in 12 patients 33-77 years old who had mild-to-severe asthma to compare the effects of these drugs on adrenal function. Low-dose ACTH tests were performed after the subjects had received inhaled beclomethasone dipropionate (200-900 microg/day) for at least 12 wk. Treatment was then switched to inhaled fluticasone propionate (200-600 microg/day) for at least 12 wk, and a second low-dose ACTH test was done. Pulmonary function was assessed on the basis of peak expiratory flow rate (PEFR, % of predicted value). After switching treatment, the daily dose of inhaled corticosteroid decreased by about 40%. Basal serum cortisol and ACTH levels were similar with both treatments. The adrenal response, as assessed by incremental rise in the serum cortisol level (peak minus basal) after ACTH challenge, improved significantly (5.6-7.9 microg/dL, p < 0.01) after switching to fluticasone. All three patients who had lower serum cortisol levels during beclomethasone treatment than during fluticasone treatment showed improvement in both the peak cortisol level and the incremental rise in cortisol. Mean morning and evening PEFRs significantly increased after switching from beclomethasone to fluticasone (morning: 71.2 to 76.0%, p < 0.01; evening: 67.3 to 72.1%, both p < 0.05). The diurnal variation of PEFR significantly decreased from 10.9% to 8.3% after switching treatment (p < 0.01). We conclude that switching from beclomethasone to fluticasone reduces the risk of adrenal dysfunction associated with inhaled steroids and improves pulmonary function.