Patients with nocturnal asthma who are clinically stable have decreased cognitive performance during the day and poorer sleep quality than their healthy counterparts. Asthma management focuses on minimizing the impact of symptoms on daily functioning and overall well-being. Nighttime symptoms traditionally have been treated with multiple medications. Recently, a newer long-acting beta agonist, salmeterol, has been used to reduce both nocturnal and daytime asthma symptoms. Lockey and colleagues evaluated the effectiveness of salmeterol in controlling nocturnal symptoms in patients with moderate persistent asthma. Safety evaluations were also conducted to correlate with overall measurements of quality of life.
Patients with an established diagnosis of asthma who had nighttime symptoms on at least six of 14 days during the baseline screening period were enrolled in this multi-center, randomized, placebo-controlled study. Exclusion criteria included pregnancy or lactation, serious medical illness, history of immunotherapy and current use of oral or inhaled beta-adrenergic agonists. Patients who met the study criteria were randomized to receive two puffs daily of either salmeterol or a placebo. Albuterol was used for breakthrough symptoms, and its use was recorded. Patients returned for follow-up visits every four weeks. At each visit, peak expiratory flow, patient diaries of symptoms and nighttime awakenings, and records of supplemental albuterol use were recorded. In addition, the Asthma Quality of Life Questionnaire (AQLQ) was administered at baseline and at each follow-up visit. The safety of the drug was evaluated on the basis of physical examination, vital signs, number of exacerbations and reports of adverse events.
A total 474 patients were enrolled in the study, with 240 in the salmeterol group and 234 in the placebo group. At baseline, study characteristics, including AQLQ scores, pulmonary function measurements and the incidence of steroid or theophylline use, were similar between groups. However, after the first four weeks and every four weeks thereafter, patients in the salmeterol group reported a better quality of life, improved peak expiratory flow measurements, reduced nighttime awakening and fewer daytime symptoms compared with patients receiving placebo. Salmeterol was well tolerated, with no clinical differences in examination findings and vital signs between groups.
The authors conclude that salmeterol is a safe, effective agent for treating nocturnal asthma. Salmeterol improved peak expiratory flow, quality of life scores and other pulmonary functions as well. In addition to the improvement in nighttime symptoms, patients reported an improved ability to carry on with their daily activities without fear of an exacerbation and with minimal side effects.