N-acetylcysteine holds little value in COVID-19 treatment

In patients with COVID-19, use of N-acetylcysteine (NAC) at high doses does not seem to prevent respiratory failure among those patients with severe disease, as shown in a study.

Inactivation of angiotensin-converting enzyme 2 by SARS-CoV-2 might lead to a local increase in angiotensin 2 expression, inducing a redox imbalance in alveolar epithelium cells and promoting apoptosis, increased inflammation and, in turn, impaired gas exchange. As such, treatment with NAC was assumed to help restore the redox homeostasis and suppress unfavorable progression in COVID-19 patients.

In the study, 135 patients (average age, 58 years; 30.37 percent male) suspected of or with confirmed severe COVID-19 were randomized to receive either NAC 21 g (approximately 300 mg/kg; n=67) or dextrose 5% (placebo; n=68) for 20 hours. All patients had an oxyhaemoglobin saturation of <94 percent or respiratory rate higher than 24 breaths/minute.

The two groups had very similar baseline characteristics, including age, sex, comorbidities, medicines taken, disease severity, as well as laboratory tests and chest CT scan findings. Following treatment, there was still no significant difference in the primary endpoint of the number of patients who were subjected to endotracheal intubation and mechanical ventilation (20.6 percent with NAC vs 23.9 percent with placebo).

Likewise, there were no significant differences noted in the secondary endpoints of time of mechanical ventilation, admission to intensive care unit (ICU), time in ICU, and mortality.