A comparison of the inhibitory effects of ketotifen and disodium cromoglycate on bronchial responses to house dust, with special reference to the late asthmatic response.

Ten patients with allergic asthma were studied to compare the inhibitory effects of ketotifen and disodium cromoglycate on bronchial responses, especially the late asthmatic response, induced by house dust allergen in bronchial provocation tests. In the first study, types of bronchial response to house dust challenge were classified from peak expiratory flow rate measurements made at intervals after the test. Nine patients showed dual asthmatic response (immediate with isolated late response) and 1 patient showed isolated late asthmatic response. The tests were treated at 1-week intervals, patients having been premedicated from the night before the test with either ketotifen (3 X 2 mg oral doses) or disodium cromoglycate (3 X 40 mg by inhalation). The results showed that both drugs produced significant protection against the immediate bronchial response and that ketotifen was at least as effective as disodium cromoglycate in inhibiting the late asthmatic response.