Effects of pranlukast, a cysteinyl leukotriene receptor 1 antagonist, combined with inhaled beclomethasone in patients with moderate or severe asthma

Background: Although inhaled steroids are used as the first line of therapy in asthmatic patients, symptoms of asthma do not improve completely in some patients. Objective: To investigate the effects of pranlukast, a cysteinyl leukotriene receptor 1 antagonist, in patients with moderate/severe asthma, when combined with beclomethasone dipropionate (BDP). Methods: Protocol 1: After a 2-week observation period, 41 patients with moderate asthma were divided into those receiving BDP at 1,600 mug/day or 800 mug/day + pranlukast (450 mg/day). The effect of treatment was evaluated by measuring AM peak expiratory flow rate, symptom score, frequency of beta (2)-agonists, and daily variability of peak expiratory flow rate. Protocol 2:39 patients participated in this study including those with moderate asthma on 800 mug/day BDP (group I), severe asthma on BDP at 1,600 mug/day (group II), and severe asthma on 1,600 mug/day BDP + 5 to 20 mg prednisolone (group III). Patients of all groups were additionally treated with pranlukast. Results: Protocol 1: Both treatment regimens resulted in improvement in each clinical parameter. There were no significant differences in the effects of two treatment regimens. Protocol 2: Pranlukast was effective in group I and II, but not in group III. In groups I and II, pranlukast tended to be more effective when BDP was introduced within the first year of onset of asthma. Conclusions: Pranlukast is effective for patients with moderate asthma and those patients with severe asthma who are not treated with oral steroids. Pranlukast is more effective in patients treated with BDP early after onset.