Adrenal suppression may be an issue in asthmatic patients. A study, published in Thorax (1993;48:599-602) looked at children who were taking 400 micrograms of steroids per day. The subjects of the study were 49 children who had a mean age of 9.2 years, taking budesonide and 28 children with a mean age of 10.2 ears taking  beclomethasone dipropionate. They were compared  to 23 children without asthma, who had a mean age of 8.9 years. Cortisol concentrations were lower in the children using the steroids than they were in the non-asthmatic controls.

Another study, published in Annals of Allergy, Asthma and Immunology  (March, 1996;76:234-238) looked at 39 asthmatic patients , 24 of whom received beclomethasone dipropionate by a metered dose inhaler attached to a spacer and 15 directly to the metered dose inhaler.  A spacer is an external device that is attached to a metered dose inhaler (MDI) to allow for better drug delivery by enhanced actuation and inhalation coordination.  The inherent advantages of aerosol drug delivery are faster onset of pharmacological action, since the drug is being delivered to the site needing therapeutic effect, and a lower systemic bioavailability, which decreases potential adverse effects.   The inhaler created adrenal suppression in 47% of the patients using the inhaler directly showed a low 24-hour urinary free cortisol excretion. Those utilizing the spacer experienced less cortisol excretion (8%).

In the Journal of Allergy and Clinical Immunology (1998;102;699-700), there is a review of four cases of patients treated with fluticasone propionate. the patients all had clinical or laboratory evidence of adrenal suppression.  This, and the other research suggest that asthma patients using inhaled glucocorticoids may also experience adrenal suppression.