Mucosal changes in the airways during long-term corticosteroid treatment.

Long-term animal studies of beclomethasone dipropionate and of budesonide and a few long-term studies of beclomethasone dipropionate in the treatment of rhinitis and asthma are available for the assessment of the possible risk of side effects. Generally speaking, remarkably few local side effects are observed, and this agrees with the striking lack of serious local side effects after widespread use of beclomethasone dipropionate for 8 years, and now the limited use of budesonide for 1 year. It is known from studies on the skin that the risk of side effects increases considerably with the potency of the compound, but it is not known whether this holds also for the use of steroids in the airways. Therefore, we do not know to what extent the high degree of safety of beclomethasone dipropionate applies also to budesonide, which may be somewhat more potent. Long-term studies with this new and interesting steroid molecule are therefore warranted. Finally, it is emphasised that the airway mucosa in the nose is well suited for the study of any local steroid effect, as it is much more readily accessible than the rather similar bronchial mucosa, and, in addition, receives a steroid dose which may be at least 100 times that applied to a given surface area in the bronchi.