Long-term follow-up of pulmonary function in bronchial asthma patients treated with pranlukast.

Clinical studies have shown that pranlukast, a selective cysteinyl leukotriene antagonist, is effective for bronchial asthma. In the present paper, we retrospectively analyzed long-term asthma control by pranlukast treatment in patients treated with inhaled corticosteroids. We analyzed medical records and asthma diaries of 21 patients (9 males, 12 females) (52.1 +/- 3.5 years of age) with bronchial asthma who experienced increase of more than 10 L/min in peak expiratory flow in the first 4 weeks of treatment with pranlukast (450 mg/day) and were subsequently treated with pranlukast for more than 1 year. They all received inhaled corticosteroids (400-1600 microg/day of beclomethasone dipropionate or equivalent). We examined clinical control in terms of time course of self-monitored peak expiratory flow. During the analyzed period, the dose of inhaled corticosteroids was tapered in 4 patients, constant in 15 patients and increased in 2 patients. In 19 patients treated with unchanged or tapered dose of inhaled corticosteroids, improvement in the increase of mean PEF at 4-week treatment was maintained for 1 year. No difference in the add-on effect of pranlukast was observed in patients treated with less than 800 microg and more than or equal to 800 microg of inhaled corticosteroids. Four patients underwent reduction of inhaled corticosteroids in the analyzed period and PEF was well-maintained and even increased by pranlukast treatment. In 11 patients in whom data for 3 years were available, the improvement in PEF persisted for 3 years. Although the present investigation is a retrospective analysis, these data may suggest that pranlukast has no tachyphylaxis and its effect continues for more than 1 year.