Used in the prophylaxis of asthma, it is administered by inhalation; it can reduce the incidence of asthmatic attacks but is of no value in the treatment of an acute attack. It acts by preventing the release of pharmacological mediators of bronchospasm, particularly histamine, by stabilizing mast-cell membranes. It is of particular use in patients whose asthma has an allergic basis; children over four may respond better than adults. It is less potent than inhaled steroids. The dose frequency is adjusted to the patient’s response but is usually administered by inhalation four times daily. Sodium cromoglycate is also used in the prophylaxis of allergic RHINITIS and to treat allergic conjunctivitis.