Efficacy of zafirlukast in the treatment of patients with bronchial asthma.

Zafirlukast is a drug newly used for the treatment of asthma. In this study, we examined the efficacy of zafirlukast on asthmatic patients and compared this efficacy between patients in different age groups and with different severities of pulmonary function. Patients concurrently inhaled long-acting beta2-agonist, corticosteroid or taken an oral aminophylline regimen, were treated with 20 mg oral zafirlukast twice daily for 6 weeks. In total, 32 asthmatic patients were included in the study. The primary efficacy measures included morning and evening peak expiratory flows (PEFs); secondary efficacy measures were the scoring of asthma symptoms including sleeping, coughing, and wheezing scores. Pulmonary functions including forced expiratory flow in 1 sec (FEV1), forced vital capacity (FVC), and PEF rate (PEFR) were examined during each clinical visit. Results showed that oral zafirlukast administration resulted in improvements in morning and evening PEFs and asthma symptom scores with the following statistical p values: morning PEF (285.8 vs 308.4 L/min), p = 0.003; evening PEF (293.3 vs 312.1 L/min), p = 0.007; coughing score (1.03 vs 0.72), p = 0.011; and wheezing score (0.71 vs 0.51), p = 0.009. As to the pulmonary function during the clinical visit, only the improvement of PEFR reached a statistically significant level (74.3 vs 82, p = 0.017). We compared the efficacy between asthmatic patients of different ages and those with different severities of pulmonary function. In patients aged below 50 years, those with FEV1 above 80% of the predicted value and FVC above 85% of the predicted value were more responsive to zafirlukast. In conclusion, we demonstrate the efficacy of zafirlukast in asthma therapy particularly for those patients who are younger and have better pulmonary function. When asthmatic patients do not respond to inhaled corticosteroid, long-acting beta2-agonist, or oral aminophylline, zafirlukast may provide an adjunct effect for asthma therapy.