Antiviral drug repurposing: different approaches and the case of antifungal drugs

In recent years, the emergence of new viruses and the re-emergence of old ones have posed a significant challenge to global Public Health. Viruses characterised by high morbidity and mortality rates have the potential to spread rapidly, causing large epidemic outbreaks and even pandemics. In this context, viral infections still lacking effective treatments represent a serious threat to human health. For this reason, sustained development and implementation of countermeasures are urgently needed against these infections, as they are for diseases for which the emergence of drug resistance is rapidly increasing. In this regard, compared to de novo drug discovery, drug repurposing could represent a highly efficient, faster, and more affordable strategy to develop new drugs. Here, we provide a comprehensive review of the different experimental and computational approaches used for drug repurposing and discuss their advantages and limitations in comparison with other drug discovery strategies. In addition, as an example of the successful application of drug repurposing, we present the case of approved antifungal drugs that could be repurposed to counteract viral infections.