Reduction of Eosinophilic Inflammation in the Airways: Study Design
Patients receiving Chinese medicines, immunotherapy, or nonspecific therapy were also excluded from this study. None of the patients had respiratory infections within 4 weeks before enrollment, or chronic bronchitis, pulmonary emphysema, bronchiectasia, or other lung diseases that could interfere with the evaluation of the efficacy of montelukast. Patients with liver disorders, renal disorders, heart disorders, or other serious disorders were excluded. None of the female patients were pregnant or lactating. The study was approved by the institutional review board of each hospital, and all patients gave written informed consent.
This study was conducted according to a randomized, doubleblind, placebo-controlled, two-period crossover design (Fig 1). The study comprised two periods, each consisting of a 2-week washout phase and a 4-week treatment phase. In period 1, after a 2-week run-in phase, the patients received the first test drug (montelukast, 10-mg tablet or matched placebo tablet) once daily between 8 pm and 10 pm. Period 2 followed the same protocol, except the patients took the alternate drug. Sputum induction by inhalation of hypertonic saline solution and airway responsiveness to histamine were evaluated during the run-in period, at the beginning of period 2, and at the end of both test periods. Patients with > 10% sputum eosinophils during the run-in period could enter the study. Blood analysis was performed at the beginning of period 1 and at the end of both test periods. Asthma symptoms were recorded in a daily diary, and PEF was monitored throughout the study periods. canadian neighbor pharmacy
Asthma Symptoms and PEF Measurement
Each patient kept a diary card during the study, detailing the intensity and frequency of symptoms, as well as the use of concomitant drugs and therapies. The symptom scores were graded according to the rating standards established by the Japanese Society of Allergology as follows: breathlessness and wheezing, on a scale of 0 to 9 (0 = no symptoms; 1 = breathlessness or wheezing; 3 = mild asthma attack; 6 = moderate asthma attack; 9 = severe asthma attack), and cough, on a scale of 0.5 to 1 (0.5 = infrequent cough; 1 = frequent cough). PEF rate was measured each morning and evening throughout the study. PEF was recorded on the diary card as the best of three successive trials with a Mini-Wright peak flowmeter (Clement Clark International; Harlow, UK).
Figure 1. Study design. A two-period, randomized, placebo-controlled, crossover study.