N-acetylcysteine as a therapeutic approach to post-COVID-19 pulmonary fibrosis adjunctive treatment

OBJECTIVE: Growing interest is directed to the outcomes of COVID-19 in survivors, both in the convalescent period and in the long-term, which are responsible for morbidity and quality of life deterioration. This article aims to describe the mechanisms supporting the possible use of NAC as an adjuvant treatment for post-COVID-19 pulmonary fibrosis. MATERIALS AND METHODS: A search was performed in PubMed/MEDLINE. RESULTS: Interstitial changes have been observed in the CT scan of COVID-19 pneumonia. In patients with respiratory outcomes in the post-COVID-19 stage, glutathione (GSH) deficiency was found and interpreted as a reaction to the inflammatory cascade caused by the viral infection, while the pathophysiological process of pulmonary fibrosis involves numerous cytokines, such as TGF-beta, TNF-alpha, IL-1, PDGF and VEGF. NAC has a good tolerability profile, is easily administered orally and inexpensively, and has antioxidant and anti-inflammatory effects that may target the pathophysiologic mechanisms involved in pulmonary fibrosis. It may revert GSH deficiency, exerts direct and indirect antioxidant activity, anti-inflammatory activity and improves immune T-cell response. CONCLUSIONS: The mechanism of action of NAC suggests a role in the treatment of pulmonary fibrosis induced by COVID-19.