Evaluation the efficacy and safety of N‐acetylcysteine inhalation spray in controlling the symptoms of patients with COVID‐19: An open‐label randomized controlled clinical trial

BACKGROUND: The aim of this study was to evaluate the effect and safety of N-acetylcysteine (NAC) inhalation spray in the treatment of patients with coronavirus disease 2019 (COVID-19). METHODS: This randomized controlled clinical trial study was conducted on patients with COVID-19. Eligible patients (n=250) were randomly allocated into the intervention group (routine treatment + NAC inhaler spray one puff per 12 hours, for 7 days) or the control group who received routine treatment alone. Clinical features, hemodynamic, hematological, biochemical parameters and patient outcomes were assessed and compared before and after treatment. RESULTS: The mortality rate was significantly higher in the control group than in the intervention group (39.2% vs 3.2%, P<0.001). Significant differences were found between the two groups (intervention and control, respectively) for white blood cell count (6.2 vs 7.8, P<0.001), hemoglobin (12.3 vs 13.3, P=0.002), C-reactive protein (CRP: 6 vs 11.5, P<0.0001) and aspartate aminotransferase (AST: 32 vs 25.5, P<0.0001). No differences were seen for hospital length of stay (11.98±3.61 vs 11.81±3.52, P=0.814) or the requirement for ICU admission (7.2% vs 11.2%, P=0.274). CONCLUSIONS: NAC was beneficial in reducing the mortality rate in patients with COVID-19 and inflammatory parameters, and a reduction in the development of severe respiratory failure;however, it did not affect the length of hospital stay or the need for ICU admission. Data on the effectiveness of NAC for SARS-CoV-2 is limited and further research is required. CLINICAL TRIAL REGISTRATION: This study Registered at Iranian Registry of Clinical Trials (IRCT20080901001165N55) dated 23-05-2020. This article is protected by copyright. All rights reserved.