Fig. 1: Anti-COVID-19 strategy.
Scientists and pharmaceutical companies are starting to develop several
types of vaccines. However, it seems that many time is required for the
results to establish a reasonable level of safety. Effectiveness of
vaccines is another important aspect because of the high amount of
variability, linked to the mutation rate of the novel virus, which could
make a previously helpful vaccine or new antiviral molecule ineffective.
Government regulatory agencies are called upon to guarantee an accurate
and careful evaluation process to satisfy all the necessary safety,
quality and efficacy requirements, avoiding any shortcuts in assessment
(Jiang, 2020).
In the absence of a known efficient pharmacological therapy and because
of the lack of time due to this public health emergency, it is
reasonable to explore any possible strategy of pharmacological
intervention. Here, an approach is discussed
considering the possibility of slowing the engraftment of the virus at
the level of the pulmonary alveoli through a pharmacological mechanism
of action. The approach would preferably be one that involves
non-specific mechanisms of action at the site of infection instead of
researching specific mechanisms of action to target the virus. To make
an urgent decision on how to focus drug research, it may be useful to
focus efforts on a therapy with known effects and safety profiles. This
has already happened with the choice of tocilizumab, approved for
rheumatoid arthritis, to block the massive release of cytokine IL6,
induced by the coronavirus at the cellular level, and thus prevent its
lethal effects. In China, more than 80 clinical trials are testing both
the newest molecules and the oldest remedies, even those from
Traditional Chinese Herbal Medicine (Maxmen, 2020), as reported in table
1. The situation that is developing is one in which there are many
studies with therapeutic possibilities but limited time.
The lung is an internal organ with a high total capacity of 6 litres, an
average surface area of approximately 50 m2, and
peculiar pharmacokinetics involving the absorption, metabolism and
elimination of substances in its lumen. Understanding the functioning
mechanisms of this vital organ, especially when targeted as in the case
of COVID-19 pneumonia, can be useful for outlining a possible
pharmacological strategy. Considering the above, here data from inhaled
antiviral aerosol studies have been reviewed and the potential use of
volatile molecules, easily eliminated and exhaled by the lungs, has been
argued. This last pharmacological strategy has never considered before
in clinical treatment and could be analysed with some limitations in
this time of crisis.