[Anti-inflammatory effects of cromones in asthma]

The cromone family comprises sodium cromoglycate and the more recently developed nedocromil sodium. Nedocromil sodium prevents the bronchial obstruction induced by a variety of stimuli, including antigen. When given before antigen inhalation, nedocromil sodium prevents the early and late reaction and the increase in bronchial hyperresponsiveness. It is still effective in preventing the late phase when given after antigen exposure. These effects may result from the action of nedocromil sodium on inflammatory cells observed in vitro, particularly mast cells and eosinophils. When inhaled regularly, nedocromil sodium improves symptoms, especially in moderate asthma, decreases bronchial obstruction and reduces bronchial hyperreactivity. Bronchial biopsy studies have shown a decrease in activated eosinophils during prolonged nedocromil sodium treatment, suggesting that the clinical benefit results from an antiinflammatory effect of the drug. More recently, it has been suggested that nedocromil sodium may act on membrane chloride channel involved in activation of many cell types. In vitro data have shown a decrease in IgE production by isolated mononuclear cells, suggesting new therapeutic potential to be studied clinically.