Effect of azithromycin on the severity of bronchial hyperresponsiveness in patients with mild asthma.

The effect of azithromycin on bronchial hyperresponsiveness was measured in a group of 11 patients with mild asthma. Azithromycin 250 mg orally was administered intermittently to all the patients twice a week for eight weeks. The only other treatment was inhaled beta2 agonist, when required. A histamine inhalation test was performed at the beginning and at the fourth and the eighth week of the study. The mean PC20 values increased significantly over the initial value at the eighth week after the administration of azithromycin (p < 0.05) but mean values for FEV1 and FEV1 percent predicted did not differ significantly. These results suggested that eight weeks of intermittent, low-dose administration of azithromycin in patients with mild asthma might reduce the severity of bronchial hyperresponsiveness.