Short-term effects of regular salmeterol treatment on adult cystic fibrosis patients

Abstract

Cystic fibrosis (CF) is characterized by chronic lung inflammation leading to airways obstruction. Bronchodilators, particularly short-acting beta2-agonists, are, therefore, often used by CF patients. The aim of this study was to evaluate, prospectively, the effects of the long-acting beta2-agonist salmeterol in adult CF patients. Twenty six patients with CF (10 males and 16 females; mean age (+/-SEM) 28+/-2 yrs) with mild-to-moderate airways obstruction (baseline forced expiratory volume in one second/forced vital capacity (FEV1/FVC) 56+/-2%) were monitored in an open, cross-over trial for 4 weeks by means of peak expiratory flow rates (PEFR), self-recorded symptom scores and body plethysmography. During a 2 week run-in period, all patients continued their treatment, including regular short-acting beta2-agonists. In weeks 3 and 4, short-acting beta2-agonists were replaced by the long-acting beta2-agonist, salmeterol (50 microg b.i.d.). Salmeterol produced a significant increase in PEFR compared to the run-in period (morning 375+/-23 vs 332+/-23 L x min(-1), deltaPEFR +15.1+/-3.1%, p<0.003; evening 384+/-24 vs 349+/-24 L x min(-1), deltaPEFR +11.7+/-2.4%, p<0.04). Similarly, patients reported lower symptom scores, e.g. less dyspnoea during the day, fewer nocturnal awakenings, less intense cough, and fewer unscheduled puffs of short-acting beta2-agonists. Thus, the long-acting beta2-agonist salmeterol provided clinical benefit to a majority of adult cystic fibrosis patients with airways obstruction. These short-term results are promising enough to set up long-term controlled studies.