[Anti-inflammatory drugs for the treatment of bronchial hyperresponsiveness]

To evaluate the effects of anti-inflammatory drugs on bronchial hyperresponse in patients with mild asthma, We examined inhaled beta 2-agonists, beclomethasone dipropionate (BDP) and suplatast tosilate. The results were as follows: 1. Inhaled beta 2-agonists, which have no direct anti-inflammatory effect, significantly improved bronchial hyperresponsiveness with inhalation of less than 6 puffs/day except tenoterol, but not with more than 6 puffs/day for two years. Patients with asthma therefore should use no more than 6 puffs/day of inhaled beta 2-agonists. Combined use of BDP and inhaled beta 2-agonists further improved bronchial hyperresponsiveness. This can be achieved by concurrent use of BDP, which has a potent anti-inflammatory effect. 2. Low dose BDP (200 micrograms/day), which is recommend in the Japanese guidelines for asthma treatment increased peak expiratory flow and improved bronchial hyperresponsivenss significantly during 8 weeks of treatment, but by 4 weeks after the end of BDP treatment, peak expiratory flow and bronchial hyperresponsiveness had worsened. Because we don't know the detail past history of patients with mild asthma, the patients must be treated with a relatively high dose of BDP (800 micrograms/day), which did improved bronchial hyperresponsiveness and significantly reduced the numbers of eosinophils and EG2 positive cells in the bronchial mucosa of patients with mild asthma. 3. Suplatast tosilate, which exerts its anti-inflammatory effect by suppressing IL-4 and IL-5 was given to patients with mild asthma for 6 weeks. Suplatast tosilate significantly increased peak expiratory flow and significantly improved bronchial hyperresponsiveness. It also signiticantly reduced the number of eosinophils and EG2 positive cells in the bronchial mucosa of eight patients with mild asthma. Therefore this drug may be useful for the treatment of patients with mild asthma.