Pyridostigmine in Severe SARS-CoV-2 Infection

We will evaluate low-dose pyridostigmine as add-on therapy to best medical care in patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and its related Coronavirus Disease 2019 (COVID-19) who require hospitalization. Our hypothesis is that, in comparison to the placebo, pyridostigmine will reduce in at least 10% a composite outcome \[death; mechanical ventilation; \>2 point-increase in the SOFA score) by day 28. We will also evaluate interleukin (IL)-6 kinetics during the first 14 days of in-hospital stay. It is estimated that 25-33% of patients hospitalized for COVID-19 are admitted to intensive care units (ICU) for severe hypoxemia. The reported mortality in those with severe disease ranges between 38% and 49%. So far, there is no pharmacological therapeutic (or else) strategy known to reduce morbidity and mortality in these patients. Mortality in COVID-19 appears to be mediated not necessarily by the direct effect of the infection, but by the disproportionate inflammatory response of the host. Pyridostigmine is an old drug that, by inhibiting acetylcholine-esterase, the enzymatic machinery that degrades acetylcholine (ACh), results in increased ACh bioavailability. ACh, in turn, ligates to nicotinic-alpha7 receptors in macrophages and T cells, resulting in reduced overactivation of these immune cells. In experimental murine sepsis, this family of drugs has resulted in reduced inflammation and mortality. Human evidence is scarce for severe inflammatory conditions. However, recent evidence from our group and others indicates that pyridostigmine has an immunomodulatory effect in people living with HIV, resulting in elevation of CD4+ T cell counts, decreased immune activation, and reduction in inflammatory mediators. Altogether, this suggests that ACh-esterase inhibitors may act as immunomodulators during viral infections, potentially reducing the inflammatory cascade (the so-called "cytokine storm") observed in critically ill COVID-