For the vast majority of children with bronchitis, 3 days of azithromycin is sufficient, because the course of acute bronchitis is mostly about 7 days, which means that most children have bronchitis for about 1 week. Azithromycin is one of the macrolide antibiotics, the half-life is very long, 3 days of azithromycin for children, can play a role in maintaining 7 days. Because the concentration of azithromycin in the child’s blood still has a therapeutic effect on bronchitis even though azithromycin is not taken for the next 4 days, azithromycin can be applied in a way that it is taken for 3 days and stopped for 4 days in the treatment of bronchitis.