University of virginia health paper in 2017 claims early administration of singulair could prevent the infection of the alveolar cells deep in the lower respiratory tract. this was in regard to viral pneumonia w/flu. would this help for covid19?

Too early to tell: Little is known about the multiple ways the virus or virus strains act. Small studies done are meant to induce hope, but they lack accuracy. Individual immunity traits play a significant role. With that said, Singulair may still protect to some extent, but timing and individual profile would be critical and hard to discern during the crisis.