The effect of salmeterol on nocturnal symptoms, airway function, and inflammation in asthma.

STUDY OBJECTIVE To determine the efficacy of salmeterol alone in a group of patients with moderate asthma with nocturnal worsening of symptoms. DESIGN Double-blind, randomized, placebo-controlled crossover study. SETTING Tertiary care hospital specializing in respiratory diseases. PARTICIPANTS Ten patients with nocturnal asthma. INTERVENTIONS Subjects were randomized to salmeterol, 100 micrograms twice daily, or placebo for 6 weeks with a 1-week washout between treatment periods. Symptoms, nocturnal awakenings, and beta 2-agonist use were recorded daily. Spirometry was performed at weeks 1 and 6 of each period at bedtime and at 4 AM, and methacholine challenge was performed at 4 AM followed by bronchoscopy with BAL. BAL fluid analysis included cell count and differential count, eosinophil cationic protein, Charcot-Leyden crystal protein, leukotriene B4, and thromboxane B2. RESULTS The percentage of nights with awakenings decreased significantly with salmeterol (69.8 +/- 8.7% vs 30.6 +/- 10.8% for placebo and salmeterol, respectively; p = 0.02). The percentage of 24-h days with supplemental inhaled beta 2-agonist use significantly decreased with salmeterol (85.9 +/- 9.4% vs 70.4 +/- 10.1% for placebo and salmeterol, respectively; p = 0.04). There were no significant differences in bronchial reactivity, 4 AM FEV1, overnight percentage change in FEV1, or indexes of airway inflammation. CONCLUSIONS Salmeterol alone improves the number of nocturnal awakenings and supplemental 24-h beta 2-agonist use in nocturnal asthma without significantly altering lung function and airway inflammation.