Morning serum cortisol concentrations after 2 mg inhaled beclomethasone dipropionate in normal subjects: effect of a 750 ml spacing device

Abstract

Large spacing devices have been shown to provide more selective delivery of an inhaled steroid to the lung but the effect on the hypothalamo-pituitary-adrenal suppression associated with high dose inhaled corticosteroids has been little studied. The effect of a large spacing device (Volumatic; 750 ml) on suppression of 0900 h cortisol after 2 mg inhaled beclomethasone dipropionate was therefore investigated in normal, healthy volunteers. Twenty four subjects (12 male, 12 female) took part in a randomised, double blind, placebo controlled cross over study in which a single dose of 2 mg beclomethasone dipropionate was taken at 2300 h on two occasions seven days apart, once from a metered dose inhaler alone and once from a metered dose inhaler attached to a 750 ml spacing device. The 0900 h serum cortisol concentration was the same on the morning before each administration (468 nmol/l, 95% confidence interval (CI) 390-561 nmol/l, day 1 v 479 nmol/l, 95% CI 463-494 nmol/l, day 8). The 0900 h serum cortisol concentration the following morning, however, was lower when 2 mg beclomethasone dipropionate was given by metered dose inhaler alone (182 (95% CI 128-264) nmol/l) than when it was given by a spacing device (363 (95% CI 281-475) nmol/l). These results suggest that a large spacing device attached to a metered dose inhaler may decrease the risk of hypothalamo-pituitary-adrenal suppression by high dose inhaled steroid treatment.