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N-acetylcysteine - A Convenient Rationale for COVID-19

Consideration of Antiviral H2S for Inclusion in one of the ANTICOV or WHO Master Protocols




With the emerging mutations and new pandemic waves, there remains a need for an effective antiviral, administered safely and easily in the early treatment phase of SARS-CoV-2, despite the current roll-out of vaccines. For antiviral options in COVID-19 two studies deserve our attention:

1--Ten consecutive severe COVID-19 cases, on the ventilator as well ECMO support, all recovered completely and fairly rapidly by high doses of N-acetylcysteine (NAC) without any mortality.

2--Another study found that serum H2S level is a prognostic marker in COVID-19 pneumonia. A low serum level H2S at admission or a decrease during infection significantly increased the risk of death in COVID-19 patients (n = 74).

Combining these two findings may give us even more options. Stepwise we explore how H2S works in viral respiratory diseases and we focus on the targets in COVID-19: the cell entry (ACE2 receptor), the virus replication (RdRp, nsp12), and the escalation of inflammation to a lethal cytokine storm (NLRP3 inflammasome). Finally, consider the question: How to administer H2S? Dissecting the degradation of NAC shows how the endogenous H2S level can be generated and with which drugs. Already 13 well-documented human cases have successfully supported this approach. The antiviral application of the endogenous H2S provides a pathway to reactivate the collapsed innate immunity as a treatment regimen for COVID-19, in early out-patient as well as later clinical situations. Further randomized controlled trials are warranted, with consideration of antiviral H2S for inclusion in one of the ANTICOV or WHO protocols.


H2S, COVID-19, acetylcysteine


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