Corticosteroid aerosols in the treatment of asthma.

Since the 1950s, corticosteroid aerosols have proved useful in the treatment of asthma. Although their precise mechanism of action is not known, these topical agents have beneficial antiinflammatory and decongestive effects on the bronchial tree in both the allergic and nonallergic forms of this disease. Four of the newer aerosolized steroids--beclomethasone dipropionate, triamcinolone acetonide, flunisolide and budesonide--have been evaluated in clinical trials. The last drug is still investigational. Their side effects are minimal, the major ones being oral candidiasis and dysphonia. They are most effective when used prophylactically and should not be administered during acute asthmatic attacks, as insufficient amounts of drug are inhaled when the airways are obstructed. Patients must be instructed in the correct techniques of administering steroid aerosols to ensure optimal therapy.