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.