Antivirals for COVID-19: A critical review

Abstract

No specific drugs have been approved for coronavirus disease 2019 (COVID-19) to date as the development of antivirals usually requires time. Therefore, assessment and use of currently available antiviral drugs is critical for a timely response to the current pandemic. Here, we have reviewed anti-SARS-CoV-2 potencies of available antiviral drug groups such as fusion inhibitors, protease inhibitors, neuraminidase inhibitors, and M2 ion-channel protein blockers. Although clinical trials to assess the efficacy of these antivirals are ongoing, this review highlights important information including docking and modeling analyses, in vitro studies, as well as results from clinical uses of these antivirals against COVID-19 pandemic.

Keywords: Antiviral; COVID-19; Coronavirus; SARS-CoV-2.

Fig. 1

The life cycle of SARS-CoV-2 and possible inhibition targets of antiviral drugs. Fusion inhibitors inhibit the fusion process of viral entry, while protease inhibitors target some proteases. Transcription inhibitors target reverse transcription step by blocking RNA-dependent RNA polymerase and therefore prevent viral replication. Some of the transcriptase inhibitors are nucleoside reverse-transcriptases. Some antivirals target M2 channel protein.

Fig. 2

Structures of selected antiviral drugs that have therapeutic potential against SARS-CoV-2. Baricitinib, umifenovir and camostat mesylate are fusion inhibitors while lopinavir darunavir and atazanavir are protease inhibitors. Reverse transcription inhibitors such as remdesivir, favipiravir (Avigan) and ribavirin, neuraminidase inhibitors such as oseltamivir and M2 ion-channel protein blockers (amantadine) are potential against SARS-CoV-2.