The increase in the incidence of bronchial asthma is not necessarily accompanied by an increase in death rates; furthermore, the knowledge of the intimate physiopathogenic mechanisms of the disease, the appearance of new drugs with pharmaceutical forms that make them more available for patients, should improve the effectiveness of the treatment. In spite of that, the asthma death rate curves increase as drug sales increase. Some authors think this is caused by factors depending on the patient, the health system and, nowadays, the inappropriate use of the available drugs is thought to be one of the reasons for the increase in asthma death rates, and the use of drugs that only supply to the patient an adequate bronchodilation may mask the underlying inflammatory process, what unavoidably leads to irreversible deteriorations in the airways, with smooth muscle hypertrophy and thickening of the basal membrane. It is logical to think that children's bronchial asthma is the first stage of a progressive illness, in which the allergic factor is really meaningful, and that is why a suitable prophylaxis with early use of drugs with antiinflammatory activity may prevent the development of irreversible deteriorations of bronchial and lung parenchyma. Oral or inhalatant corticoids, disodium cromoglycate, ketotifen and nedocromil are the drugs with well-known antiinflammatory activity, though they have a different site of action, as corticoids act directly on inflammatory cells, inhibiting the activity of macrophages and particularly of eosinophils, while cromoglycate, nedocromil and ketotifen inhibit mediators release, thus stabilizing mastocyte membrane.