Effect of pranlukast, a leukotriene receptor antagonist, in patients with severe asthma refractory to corticosteroids.

We investigated the effect of pranlukast (ONO-1078), a cysteinyl leukotriene receptor antagonist, in 11 patients with severe bronchial asthma. The patients had been treated with 1600 micrograms/day of beclomethasone or 800-1600 micrograms/day of beclomethasone plus 2.5-20 mg/day of prednisolone, but remained symptomatic. After a 2-week baseline period, the patients received 225 mg of pranlukast twice daily for 8 weeks. Morning and evening peak expiratory flow rate (PEF) and symptom scores (cough, dyspnea, sleep) were recorded in an asthma diary. Ten patients completed the study. Symptom scores, especially dyspnea and sleep scores, and the number of rescue beta 2-agonist inhalations were significantly decreased. The morning PEF significantly improved from a mean baseline value of 311 to 341 L/min by the end of the study period. The evening PEF also improved, from 328 to 348 L/min, although the difference was not significant. These results suggest that pranlukast may be effective in treating patients with severe asthma who are refractory to corticosteroid therapy.