IRCT20100102002954N24 IRCT 2021-06-13 Shahroud University of Medical Sciences The effect of azithromycin on the prevention of asthma attacks The effect of azithromycin on the prevention of asthma attack in patients with chronic asthma, a clinical trial 2021-05-31 anticipated 116 Complete https://irct.ir/trial/56156 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Patients were allocated to intervention and control groups according to random allocation table that illustrated by a statistician. Randomization was done using permuted block randomization method (Block size was 4) using blocked random allocation syntax in SPSS software. For calculation sample size was 116 and number of blocks was 29. Allocation concealment was done using closed opaque envelope. 2-3 Chronic Asthma. Intervention 1: Intervention group: for patients in the intervention group, in addition to routine treatments involving the use of inhaled sprays (airway dilators and corticosteroids) , azithromycin 250 mg capsules twice daily for the first day and then daily for four days. The next is given and from the second week to the twelfth week, three capsules (one day in between) of this capsule are prescribed. Intervention 2: Control group: for patients in the control group, only routine treatments involving the use of inhaled sprays (airway dilators and corticosteroids) will be prescribed for 12 weeks. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is After completing the research and summarizing the results, a decision will be made in consultation with the facilitators and colleagues.