Abstract

Viral infections, which lack effective treatment, have posed an ongoing threat to human health. Most approved antiviral agents selectively target a single virus, providing a “one drug-one bug” solution. However, this approach has limited efficacy, particularly with emerging and re-emerging viruses with no specific, licensed antiviral drug or vaccine.

Since the outbreak of the COVID-19 pandemic, tremendous studies have focused on the effect of some (broad-spectrum) antiviral agents on this emerging virus. The concept of broad-spectrum antivirals refers to the group of drugs with the capability of combating more than one virus rather than “one drug-one bug” agents. This approach may offer a new horizon for the management of emerging viral threats.

Among BSAs, nucleotide and nucleoside analogs target enzymatic functions shared by some viruses, thus, inhibit their replication. An alternative approach of BSA agents is to target host factors commonly required by multiple viral pathogens, on which the viruses intimately rely. For example, anti-malarial agents (chloroquine and hydroxychloroquine) inhibit acidification of endosomes, an essential process for uncoating of some RNA viruses, kinase inhibitors impair intracellular viral trafficking, and statins attenuate replication of some enveloped viruses.

In this review, we will shed light on BSA agents with potential efficacy against SARSCoV- 2 infection. The time-consuming process of new drug development makes repositioning drugs, already approved for use in humans, the only solution to the epidemic of sudden infectious diseases as COVID-19.