A new study has identified a potent diuretic ethacrynic acid as an efficient inhibitor of SARS-CoV-2, the virus that causes Covid-19 infection.

The study, published in the journal Viruses, suggested that ethacrynic acid, a "water pill" (diuretic) that works in kidneys to increase the amount of urine and helps the body get rid of extra water, can be repurposed to treat Covid-19.

For the study, the researchers have conducted silico analysis, molecular docking experiments, and activity assays to identify potential inhibitors of SARS-CoV-2. They also intended to understand the molecular orientation and binding affinity between molecules.

The researchers have conducted a series of in vitro experiments to determine the effect of certain inhibitors. These include Ciclesonide, Delafloxacin, Dutasteride, Netupitant, Tadalafil, Saquinavir, on the virus's main protease.

According to the findings, none of these inhibitors have shown significant inhibitory activity against SARS-CoV-2 main protease.

However, the analysis found a favourable interaction pattern between ethacrynic acid and main protease.

Notably, the scientists have observed that ethacrynic acid can inhibit the main protease at a very low concentration (in the 8 – 9.5 µM range). This makes ethacrynic acid the most potent protease inhibitor compared to other approved inhibitors, such as boceprevir and GC376.

The researchers, however, have cautioned that because ethacrynic acid is a strong diuretic, excessive use can impair the fluid balance of the body.