Can early and high intravenous dose of vitamin C prevent and treat coronavirus disease 2019 (COVID-19)?
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The
COVID-19 (SARS-2-Cov) pandemic, first reported in Wuhan, China, is now
spreading to many continents and countries, causing a severe public
health burden. Currently, there is no vaccine or specific antiviral drug
for this deadly disease. A quick, deployable and accessible, effective
and safe treatment is urgently needed to save lives and curtail the
spreading. Acute respiratory distress syndrome (ARDS) is a key factor of
fatality. Significantly increased oxidative stress due to rapid release
of free radicals and cytokines is the hallmark of ARDS which leads to
cellular injury, organ
failure and death. Early use of large dose
antioxidants, such as vitamin C (VC) may become an effective treatment
for these patients. Clinical studies also show that high-dose oral VC
provides certain protection against viral infection. Neither intravenous
nor oral administration of high-dose VC is associated with significant
side effects. Therefore, this regimen should be included in the
treatment of COVID-19 and used as a preventative measure for susceptible
populations such as healthcare workers with higher exposure risks.
Coronaviruses and influenza are among the pandemic viruses that can cause lethal lung injuries and death from ARDS [[1], [2], [3]].
Viral infections could evoke “cytokine storm” that leads to lung
capillary endothelial cell activation, neutrophil infiltration and
increased oxidative stress (reactive oxygen and nitrogen species). ARDS,
characteristic of severe hypoxemia, is usually accompanied by
uncontrolled inflammation, oxidative injury and damage to the
alveolar-capillary barrier [4].
Increased oxidative stress is a major insult in pulmonary injury
including acute lung injury (ALI) and ARDS, two clinical manifestations
of acute respiratory failure with substantially high morbidity and
mortality [5,6].
In
a report of 29 patients with COVID-19 pneumonia, 27 (93%) showed
increased hsCRP, a marker of inflammation and oxidative stress [7].
Transcription factor, nuclear factor erythroid 2 (nfe2)-related factor 2
(nrf2), is a major regulator of antioxidant response element
(ARE)-driven cytoprotective protein expression. Activation of Nrf2
signaling plays an essential role in preventing cells and tissues from
injury induced by oxidative stress. VC, an important component of the
cellular antioxidant system [8], is beneficial to critical care management [9]. Cytokine storm is observed in both viral and bacterial infections [3]
and results in increased oxidative stress via a common and non-specific
pathway. Since the prevention and management of oxidative stress could
be realized by large dose of antioxidants, this approach may be
applicable to COVID-19 with intravenous high-dose VC based on the
outcome of three previous clinical studies involving a total of 146
patients with sepsis [10].
Hemila
and colleagues reported that various high-dose intravenous VC infusions
(e.g., 200 mg/kg body weight/day, divided into 4 doses) shortened the
intensive care unit (ICU) stay by 97.8% [11], accompanied by a significant reduction in the mortality rate [12]. Such an experience was reproduced among patients ill with severe influenza [13,14].
Indeed, dietary antioxidants (VC and sulforaphane) were shown to
decrease oxidative stress induced acute inflammatory lung injury in
patients receiving mechanical ventilation [15]. In addition, oral VC (e.g., 6 g daily) was able to reduce viral infection risk [16] or to improve symptoms [17].
High-dose
intravenous VC has also been successfully used in the treatment of 50
moderate to severe COVID-19 patients in China. The doses used varied
between 2 g and 10 g per day, given over a period of 8–10 h. Additional
VC bolus may be required among patients in critical conditions. The
oxygenation index was improving in real time and all the patients
eventually cured and were discharged [18].
In fact, high-dose VC has been clinically used for several decades and a
recent NIH expert panel document states clearly that this regimen
(1.5 g/kg body weight) is safe and without major adverse events [19].
Because
the development of efficacious vaccines and antiviral drugs takes time,
VC and other antioxidants are among currently available agents to
mitigate COVID-19 associated ARDS. Given the fact that high-dose VC is
safe, healthcare professionals should take a close look at this
opportunity. Obviously, well-designed clinical studies are absolutely
needed to develop standard protocols for bedside use.
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